they are cool cars with some real potential to be quarter mile missiles.
Do you like the car? is the car in good overall condition for the year?
No used car is flawless, and obviously a cheap car is no expection, there will be things that break and go wrong, that is what happens when you don't buy new. The question is wether or not it's worth it to you. Some people will tell you no it's not worth it, others will tell you it's definatly worth it. It really depends on your comfort with fixing things, and spending some money on it. Look it over, see how much work it's really going to need, and then make your decision based on your finances and how you feel about the car. If it's something you REALLY want, it's worth more to you than it is to someone who doesn't care about supra's. Personally, I would probably buy the car anyways.
If the problem is a new one that wasn't in the original description, see if you can get a couple hundred bucks nocked off because of the problem. It's worth a shot.