I don't know if I would use it because I don't think that I run into the "problem" more than 2-3x a year. Maybe it's more often - I don't know - but it isn't a problem that I want solved.

If this was craigslist related, then I would be interested though. This is just my personal shopping habit but I find this problem more with auction-based sites like ebay/craigslist than other online system. If I could specify specifics - model, price - then it would be awesome!