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Show HN: I made a price aggregator to find the best PC parts deals across eBay

20 points by tzoSkatzo 2y ago

Started PC flipping as a hobby (buying used parts, building PCs, and selling them for a small profit). Found that focusing on used parts on eBay gives the best margins - like finding a GPU 20% below market, pairing it with other deals, and selling the complete build locally. I discovered that eBay marketplaces (.com, .de, .co.uk etc.) often have different prices for the same items! Or just completely different items. So I built an eBay price scanner for PC components. It scans listings across different Ebay markets, calculates median prices, and flags anything selling below market (including shipping costs to your location). It basically finds the best deal that is specific to your location. It currently tracks GPUs, CPUs, RAM and motherboards across 6 eBay markets, updating every 8 hours. Been using it myself for and it actually works! Let me know, what you think. Would love to hear your feedback on making it more useful.

tzoSkatzo 2y ago
Technical detail for those interested: Architecture: - Frontend: Vue.js with Tailwind CSS, hosted on Vercel - Backend: Python scripts running on Oracle Cloud VM - Data refresh: Every 8 hours via cronjob The most interesting challenge was filtering legitimate PC part listings. eBay search isn't perfect - searching for "RTX 4090" returns lots of irrelevant items like brackets, broken cards, or water cooling kits. I solved this using custom ML classifiers for each component type (GPU/CPU/RAM/Motherboard). Each classifier is trained on labeled eBay listings to identify legitimate parts. This automated filtering is crucial since the scanner processes thousands of listings daily across different eBay markets and languages. One other issue, is bypassing the eBay API limitations, since I query for thousands of items I need to somehow optimize it. So far, I'm caching useful information like Shipping, but eventually if I want to add more items and/or marketplaces, I will need to either implement a key rotation or ask ebay to extend their API limits. Currently, I scan for around 10k eBay listings along with their shipping info.
atmanactive 2y ago
How do you confirm that the GPU you bought from eBay is really in 100% working order? CPUs are clear case: they either boot up or they don't. If they do boot up, they are 100% ok. RAM, you do memTestx86 and it's all clear. But MBDs on the other hand ... I had ~50% failure rate from eBay where a MBD would boot up and would look like it is working correctly, only to discover that there is something somewhere that's not working as expected months later. Hence, I'm curious about your approach to GPUs.
- zoky 2y ago
  > CPUs are clear case: they either boot up or they don't. If they do boot up, they are 100% ok. Not necessarily. I had a Xeon once with a single bad core. It would boot fine and run for a while, but under heavy loads it would produce bad results, leading to a kernel panic due to a detected inconsistency. Disabling the defective core made the problem go away, so I eventually had the CPU replaced which fixed the issue. I also had a Core i7 system recently that was experiencing inexplicable slowdowns while rendering video for a month or two. After replacing literally every other component in the system without resolving the problem, the CPU finally died and I was forced to replace it. The slowdowns went away immediately, so my conclusion was that the CPU was on the way out and that was causing the performance problems.
  - atmanactive 2y ago
    Interesting. That never happened in my experience. Which generations were those defective ones? I mean, yes, overclocking and/or overheating the CPU could damage it, but I thought Intel had every possible self-defence protection enabled in the CPU.
    - zoky 2y ago
      The defective Xeon was in a 2009 Mac Pro, so it would have been a Westmere-era processor. Even though I was certain the problem was a bad core, the guy at the Genius Bar refused to believe it was the processor. He finally grudgingly agreed to replace the processor if I really wanted, but assured me it wouldn’t solve the problem. Unsurprisingly though, it did. The other processor was an i7-14700K, and it was about eight months old when the problems started to manifest. The processor was never overclocked, and had a pretty chunky heatsink (with no fewer than three fans) so I’m pretty sure it was never run out of spec. Intel ended up RMAing the processor without too much hassle, so I get the sense that what had happened was not entirely uncommon, and they really want to avoid any bad press relating to it. I’m not convinced Intel’s thermal protection is all that effective these days, after reading reports of people claiming their processors have become physically warped. Apparently a popular PC mod involves replacing the “flip-down” CPU bracket with one that screws in at all four corners, supposedly to help prevent warping.
dotcoma 2y ago
My 2 cents: I’d call the website (top left-hand) PC Price, not PC Scanner, as the URL is pcprice.watch
- tzoSkatzo 2y ago
  Thanks for the feedback, I agree so I updated the title.
atmanactive 2y ago
About the search: I just did my first search for the RTX 3050, but the very first result is GTX 1660. Given that this happens all the time on eBay, and, obviously on your site as well, I think there should be a cookie-based hide-this-one-forever UI affordance and functionality to alleviate this problem.
- tzoSkatzo 2y ago
  Yeah, it's funny the eBay API tends to return mostly irrelevant listings, and I have to classify them. Even then they are like 95% accurate, one thing I could potentially improve is use a classifier per model instead of per part type. However, your feedback is noted, I'll try to add this asap.
brokenmachine 2y ago
Nice site, great job.
totaldude87 2y ago
This is good start, i guess to make it more helpful, you can also do a pre configured builds so folks who just want to check the overal price can do that. Also , why not do it for more things? like cellphones are hot on ebay, and i would love to use this kinda of a tool
- tzoSkatzo 2y ago
  Thanks for your feedback! Actually I've thought of that as well, but my main concern is that it's a bit difficult to find out median prices for "non-standardized" items, and I want to offer a price comparison that is meaningful for users. So cellphones are possible, but prebuilts could be trickier. It would be an interesting challenge to tackle eventually, if eBay offers me more API calls than they currently offer.

20 points by tzoSkatzo 2y ago

tzoSkatzo 2y ago

Technical detail for those interested: Architecture: - Frontend: Vue.js with Tailwind CSS, hosted on Vercel - Backend: Python scripts running on Oracle Cloud VM - Data refresh: Every 8 hours via cronjob The most interesting challenge was filtering legitimate PC part listings. eBay search isn't perfect - searching for "RTX 4090" returns lots of irrelevant items like brackets, broken cards, or water cooling kits. I solved this using custom ML classifiers for each component type (GPU/CPU/RAM/Motherboard). Each classifier is trained on labeled eBay listings to identify legitimate parts. This automated filtering is crucial since the scanner processes thousands of listings daily across different eBay markets and languages. One other issue, is bypassing the eBay API limitations, since I query for thousands of items I need to somehow optimize it. So far, I'm caching useful information like Shipping, but eventually if I want to add more items and/or marketplaces, I will need to either implement a key rotation or ask ebay to extend their API limits. Currently, I scan for around 10k eBay listings along with their shipping info.

atmanactive 2y ago

How do you confirm that the GPU you bought from eBay is really in 100% working order? CPUs are clear case: they either boot up or they don't. If they do boot up, they are 100% ok. RAM, you do memTestx86 and it's all clear. But MBDs on the other hand ... I had ~50% failure rate from eBay where a MBD would boot up and would look like it is working correctly, only to discover that there is something somewhere that's not working as expected months later. Hence, I'm curious about your approach to GPUs.

zoky 2y ago
> CPUs are clear case: they either boot up or they don't. If they do boot up, they are 100% ok. Not necessarily. I had a Xeon once with a single bad core. It would boot fine and run for a while, but under heavy loads it would produce bad results, leading to a kernel panic due to a detected inconsistency. Disabling the defective core made the problem go away, so I eventually had the CPU replaced which fixed the issue. I also had a Core i7 system recently that was experiencing inexplicable slowdowns while rendering video for a month or two. After replacing literally every other component in the system without resolving the problem, the CPU finally died and I was forced to replace it. The slowdowns went away immediately, so my conclusion was that the CPU was on the way out and that was causing the performance problems.
- atmanactive 2y ago
  Interesting. That never happened in my experience. Which generations were those defective ones? I mean, yes, overclocking and/or overheating the CPU could damage it, but I thought Intel had every possible self-defence protection enabled in the CPU.
  - zoky 2y ago
    The defective Xeon was in a 2009 Mac Pro, so it would have been a Westmere-era processor. Even though I was certain the problem was a bad core, the guy at the Genius Bar refused to believe it was the processor. He finally grudgingly agreed to replace the processor if I really wanted, but assured me it wouldn’t solve the problem. Unsurprisingly though, it did. The other processor was an i7-14700K, and it was about eight months old when the problems started to manifest. The processor was never overclocked, and had a pretty chunky heatsink (with no fewer than three fans) so I’m pretty sure it was never run out of spec. Intel ended up RMAing the processor without too much hassle, so I get the sense that what had happened was not entirely uncommon, and they really want to avoid any bad press relating to it. I’m not convinced Intel’s thermal protection is all that effective these days, after reading reports of people claiming their processors have become physically warped. Apparently a popular PC mod involves replacing the “flip-down” CPU bracket with one that screws in at all four corners, supposedly to help prevent warping.

dotcoma 2y ago

My 2 cents: I’d call the website (top left-hand) PC Price, not PC Scanner, as the URL is pcprice.watch

tzoSkatzo 2y ago
Thanks for the feedback, I agree so I updated the title.

atmanactive 2y ago

About the search: I just did my first search for the RTX 3050, but the very first result is GTX 1660. Given that this happens all the time on eBay, and, obviously on your site as well, I think there should be a cookie-based hide-this-one-forever UI affordance and functionality to alleviate this problem.

tzoSkatzo 2y ago
Yeah, it's funny the eBay API tends to return mostly irrelevant listings, and I have to classify them. Even then they are like 95% accurate, one thing I could potentially improve is use a classifier per model instead of per part type. However, your feedback is noted, I'll try to add this asap.

brokenmachine 2y ago

Nice site, great job.

totaldude87 2y ago

This is good start, i guess to make it more helpful, you can also do a pre configured builds so folks who just want to check the overal price can do that. Also , why not do it for more things? like cellphones are hot on ebay, and i would love to use this kinda of a tool

tzoSkatzo 2y ago
Thanks for your feedback! Actually I've thought of that as well, but my main concern is that it's a bit difficult to find out median prices for "non-standardized" items, and I want to offer a price comparison that is meaningful for users. So cellphones are possible, but prebuilts could be trickier. It would be an interesting challenge to tackle eventually, if eBay offers me more API calls than they currently offer.