It's worth the money to have a mechanic, of your choice, check out the car. He won't charge much to put up on a lift and inspect everything. Don't waste your time with Carfax, it's not worth the paper it's printed on.
a simple thing is to definitely check that the oil is not black and don't have a funny smell. Also smell the radiator area. If it smells like "syrup" chances are it has over heating problems or has over heated in the past which could be a big problem because over heating can cause blown head gaskets! You don't want engine trouble or tranny trouble!