First off, that is a pretty good price. 3rd gen. 4Runners (2000, 01 and 02) can sell for that or higher. 90,000 miles is not terrible. First thing I think of, does it have the black plastic sides or does it look like most 4th gen 4Runners. The black plastic sides was never a favorite to a lot of people and people selling those, there is a slight discount. One thing, I can guess the timing belt was not done and it would or should be done at 90,000 miles. Other things to look for are the normal things that a good mechanic could catch. Also, the V6 had some problems in 03, but the V8 was fine. If things check out, I would think it could be a good vehicle.