Buying 04 tiburon

I have a friend that wants to sell me this car. It has 170,000 on it. The body is in great shape just the doors have a little surface rust. I do know the transmission shifts hard into 3rd gear. He bought it with 140,000 and not change the tranny fluid. But has taken good care of everything else. It is really dirty. So I doubt I can change the filter and fluid and will be fine with I could do the and problem be fixed. So I got to put a tranny in it. Other then that the car is awesome. He is a friend and wants rid of car. Got another car. Told me $600. What is everyone's opinion