pretty damn cheap.
mine was just given to me in non running condition.
the body is freakin' straight other than a dent in the door.
see what they're asking for it.
http://www.club-s12.org will actually be of more use.
there's not a lot in the way of an aftermarket...but it's fun to try anyway.
suspension wise, it shares the front end with the 280ZX and the IRS from the 300ZX. (Z31)
the turbo motor makes 122hp I think...weight is somewhere around 2400lbs...they're fun to drive but I haven't driven a turbo model yet being as mine isn't running.
in average shape...I wouldn't pay more then 1200 for one honestly....anymore then that and you can find a decent S13 with a giant aftermarket.