When I picked up my '90 last year with 64,000 miles on it, the previous owner only did oil changes, nothing else.
So, in the space of a few months:
Replace all belts...$40.00
Steel idler pulleys..$30.00
New rad hoses.....$20.00
Plugs and wires..$100.00
Upper ball joint...$150.00
Alignment..............$60.00
Supercharger oil....$20.00
Crank sensor.........$65.00 (This is why I got it so cheap, the previous owner could not figure out why it would sometimes cut out, or not start)
Cam sensor...........$25.00
Complete rear brake rebuild..$250.00
New accumulator......$100.00
New battery...........$65.00
New starter............$150.00
3 row rad...............$200.00
Water pump..............$65.00
New tires.................$500.00
Fix crack in rear seat..$150.00
Fix cracks in dash.......$130.00
Convert to R134a.......$150.00
After doing this, I have gone over a year without doing anything.
However i just bought the parts to rebuild my shifter...$60.00.
Good thing I do most of this myself.
And here she is,
http://www.sccoa.com/forums/showthread.php?threadid=26634