Yeah, the Diablo Predator works the same way. Once you download the program to the PCM, the unit is locked to that VIN. When you restore the stock tune, the unit then becomes unlocked and can be used on a different VIN vehicle. I've since purchased HPtuner and EFIlive, but still keep the Predator around anyway. It's better suited to checking and clearing error codes for me....
Pretty much all of the tuners, whether handheld or PC based are going to put restrictions in place to limit the number of tunes you can do for the set fee you paid. Unless you want to spend several thousand bucks to get the full blown tuner version that allows unlimited tunes, you should expect to be limited in some fashion or another for the base price.
Looking at it from their perspective, unless they did it that way, anyone could pay the base price and then go to town doing unlimited tunes to other folks cars. Obviously they are in this business to make money, so they would rather sell a bunch of their units than to have one guy giving away free tunes all day long.
Now, that being said, it is EXTREMELY doubtful that whoever put that Hypertech on auction didn't know all this beforehand. He was basically auctioning off a paperweight. I believe the Predator, even after being locked can still check and reset error codes on other vehicles, but I'm not sure about the Hypertech.