Have a mechanic check it out and then decide what to offer them. If the whole thing is in mint condition then the price is ok. You can get them for cheaper, however they are also more likely to have problems. You are going to spend the money. Do you want to spend it on the purchase or on parts?
I just bought mine in July and I've had to replace the alternator, battery, rims, window switch, transfer case and I had to fix a starting problem in my steering column. I now need to fix my exhaust, my floorboards are cracked, my drivers seat is busted and my radius arm bushings need to be replaced soon. The good thing is that most of these wont need to be fixed again soon, but I had to spend the money. When I bought it I thought only the drivers seat was busted..Surprise!
All that said I love my Bronco..its my third one. Alot of what I've gone thru is part of buying a 10+ year old vehicle. At first the costs are always higher. You are much better off spending more on the initial purchase over spending money on parts and downtime.