craigslist/ebay flipping - find stuff that seems to be underpriced, badly described/advertised, or worth more than the seller is asking because of some feature

craigslist/ebay flipping - find stuff that seems to be underpriced, badly described/advertised, or worth more than the seller is asking because of some feature that you have special knowledge of but they don't, buy it, then turn around and sell it for a profit (hopefully!)