It was low, but not dirt cheap. It was an older copy of the software, one that was no longer upgradeable. I figured it was either a scammer, or someone stuck with a copy and trying to get rid of it while it was still worth something. Amazon says they have an "A to Z guarantee", that covers any issues so "buy with confidence". They want me to contact the seller before they will go that route, though. The seller already had positive feedback, which tells me some people don't mind doing business like this or don't know he's selling them counterfeit. Since their last email said "if you're the copyright holder, let us know", I'll probably just contact the maker and let them sort it out.
Edit (ogre posted while I was writing): I thought about contacting them, but I'll see what the maker has to say first.
[This message has been edited by kwagner (edited 01-17-2011).]