D & H: Can't help much on a reasonable purchase price. Sounds like it
would be a good vehicle to own. I wouldn't be too quick to change
engines. If the PO took good care of the cooling system, IE: used the
proper coolant and has had no problems, then there's a good chance the
engine has many miles left and then it can be rebuilt. My '86 has 184k
with a rebuild at 157k. The '90 has 138k with no work on the engine at
all. 
Good luck!!

Steve and Jo Ann Wacker
San Marcos, Ca 
90 Carat
86 Syncro