20 years ago, you could hang your hat on the low mileage. But that doesn't matter (so much) anymore, as the age thing does.
All the rubber and vinyl bits have outgassed the chems that make them soft. They may look fine but just as soon as you start to flex them they will break up. Well, in time any way. The tires, tubes and rim strips are shot regardless of the mileage (age 6+ years), the insides of the cables get microscopic corrosion from temperature cycles even in heated garages, there is still condensation. I could go on. Everything won't have to be replaced at once of course. The point being don't get too awe struck, if its going to be a rider, its going to take some money. And effort.
Shoot for $500, pay $800. If it were a runner with tires and reliable starting, it would be worth more. With a question mark on the engine, be careful. AS long as you have the proper expectations, you will be fine.
PS: Just saw the post on the GF uncle. Whats a few $ between friends? Get it running w/ tires first. Yes it could be worth $2k+ at that point. Soak all the rubber and vinyl (seat especially, before you sit on it) in a product that rejuvenates such things.