Chances are high that finding a well maintained MA70 in the states anymore, is coming from the original owner.
Other than irresponsible, unaware owners of these cars, a majority of the 'trash' A70's out there are cars that have been handed around a lot with owners that just don't realize what they have.
Go track down all the original purchasers of their 1986.5 to 1992 Supra, and ask, to them, what their car should be worth. Besides, it's all just a matter of what part of the world/country you live in.
By most peoples standards, I got my car for an absolute steal, However, to some, I'd have paid way too much.
Jeff