This will work if you are located in big western city. He bought his Z420 for 50$, and when I check ebay right now they are going for 150-300$ + 100-200$ shippi

This will work if you are located in big western city. He bought his Z420 for 50$, and when I check ebay right now they are going for 150-300$ + 100-200$ shipping. And that with E5-1603 CPU, not the E5-2667 or similar. Lets say I have 5 year old AMD FX-8350 due to upgrade this year. That Xeon is actually slower, looking at some basic benchmarks (of course it may be faster in some, but I don't have time for detailed investigation). So ~300$ total for a sidegrade? And that not including hassle with shipping, maybe dealing with scammer seller from ebay, then import tax 30% (and who knows how base price will be calculated at customs). Etc. etc. Not worth it. I'm not saying that upgrading for cheap is bad of course, but getting stuff like described in the article is borderline lottery win in most of the countries. You can't depend on it or plan in advance.