Right now eBay is already sitting on this data. In addition to the sale/non-sale price data, recently they've began to encourage (and sometimes force) you to v

Right now eBay is already sitting on this data. In addition to the sale/non-sale price data, recently they've began to encourage (and sometimes force) you to very specifically categorize the item you are selling. Combine with geolocation data for the buyer and the seller and they probably have a greater trove of data then you could get even with a biz dev deal with Craigslist -- main issue is that you have no idea whether an item in a given post was actually sold, and if so for how much. I fear Priceconomics.com, as interesting as it is, will just work hard to prove a business model for this data that if successful will just be exploited by some engineers working at eBay who spin up a product to compete.