what is a salvage title coupe quattro worth?

[Rebecca Ruston]

I'm in Oregon, looking at a '90 coupe quattro with about 250K and its been wrecked, so it has a salvaged title, and a mismatched door with no window. It has no stereo and other minor interior issues, but seems to run fine.
I don't mind putting in some work, and a new door (if I found one) or a new window (more likely), but I don't really know what something like this is worth.

I really love these cars and would enjoy having this to play with and work on, but I rarely hear about one in this kind of condition so I'm not sure what to offer the guy.

any opinions greatly appreciated

-Rebecca