I was going for a GLI with a 9a motor, and they're a dime a dozen compared to a 16v GTI with a 9a. They bluebook for about $2k which was within my budget. I picked up mine for $1700 and I thought that was a decent price for what I got. I've come to the conclusion that the people before the previous owner took good care of the car but I'm led to believe that the PO didn't bother with maintenance and read from a manual written by Mickey Mouse.
VW made about 4k GTI's in 1992 and most of those are 8v GTI's. The majority of the thousand or so 16v GTIs left have either been wrecked, parted out, or have had all of the OEM parts that make them special swapped out for something else. Those reasons are why your car commands a $7.5k price tag and why its twin, even though its a touch high IMO, is asking $9.5k. That's also why my cheap ass will probably never own one and why I like yours so much.