fridge and ac compressors

I sell fridge compressors locally to used appliance stores and have been doing so for 15 years. I have never tried selling them on Ebay though. I sort them by manufacturer and BTU rating. As far as testing them, I make sure they fire up right and check the running amps first. Then I make sure they do a good frost pattern on the evaporater. It's also important to make sure they don't have broken motor mounts (clunking when they cycle off).