Depends on your location to some extent. In south Africa the supra was never officially imported. There must be less than 30 supra in the entire country. Getting an import permit to import legally is also nigh on impossible. Due to this when they do come up for sale,ridiculous prices are called.
In the last 2 years I've seen a few na supra sell for the equivalent of 8000pound. Tts sell well in excess of 10000pound regardless of spec. Both these examples do not take into account stock body or bodykit or extras. As long as a supra comes up for sale in whatever condition it will sell.
The market is very different here. We don't have the luxury of taking a"purist" approach for such a car.
Take a look at the us market for example. Astronomical prices are paid for the supra and skyline r32/33/34. Legislation and import restrictions and other policy plays a big part in the pricing of cars like these.