As I figured, the paint didn't match the Vintage-trek chart for a 750. You're seller may have screwed up, but a ready-to-ride bike with $40-$50 worth of baskets, $50 worth of new tires/tubes, is a good deal IMHO. I can sell a 730 for $225-$250, without extras.

I have a twenty something Trek Multi Track 700, probably a 1992. It rides well and I can comfortably ride many miles on it. I paid next to nothing for it, but I had to overhaul it, which is about $175-$200 at REI. Then last year, I upgraded the shifters and drivetrain, when the grip shifter crapped out, and switched all the black components for silver. Cheap Shimano Tourneys and Deore. Like many manufacturers, the same frame is used over 3 or so models, just varying the component grade. Here is a photo from two weeks ago. The two teen bike valets at Bike NYC, were so wowed by the bling (must be the $3 handgrips), I heard one say to the other, "I want this one," even after spending all day looking at much more expensive and current bicycles.