It all depends on what you want to do with it. If you're buying it to have fun with, just make sure all the rigging is functional and safe, the stringers have no delamination, the hull and deck have no cracks or holes and is structurally sound, and everything is mounted correctly. Back in the day there were some boats that were manufactured just to get them out the door and there were some problems with them. After 20-30+ years most of these boats have either had the bugs worked out, or are in the scrap heap.
If you're planning on making it a 90-100 MPH boat, I'd really look into it in more depth. Maybe look for a boat that was better set up for those speeds. Most of the boats were manufactured as family fun boats and not meant for those types of speed.
This is just my 2cts. There are others here more qualified to answer this than I am, but again, it's all based on what you want to do with it.