I went to a supra meet last spring. As usual it was mostly MK4 supras and only 2 MK3's including me. What I noticed was that most of the MK4's there were really showing age (faded seats, worn down carpet, faded paint). My 92 MK3 looked just as good or better than some the MK4's there. It amaises me that these guys can still get $25k+ for these cars just because of there so called "potential".
I believe an MK3 can still get OK money, but it has to be in very good condition. But it will never get that much because of the reputation it has. When people think about MK3's, they think of BHG's and crappy condition, and not making 700rwhp and running 10 second 1/4 miles.