The engine is the biggest issue. They can be a bit to source but if you take your time you may be able to unfreeze it. No inside pictures but I would say you are looking at a 500 to 700 car. gt6+ I think are the most desirable so the tend to bring best price if they are done right.
All rubber has to be done, interior is gone so most of that would need to be redone. My guess is the floors are gone and the rockers and back bottom fender. Need more pictures to really tell.
But I have gotten for less then 500 in none runner condition and the engine is the part that could be hard to find and expensive to find the right one for that model.