Maintenance is not a good place to try and save money, especially on a coach this size and age. If they have the documentation to prove that claim fine. Just realize the oil change is going to be due again in a few months. Additionally, you're going to want to know about fuel filters and an air filter that can be expensive. If not done recently, you'll be doing them soon.
8k is a good price for a DP in good condition. I would want some assurance it IS in good condition both mechanically and from an RV perspective, and if I were not qualified to make that call, I would bring people in that are qualified.
If you find you're looking at a decent coach after the insprections, offer anything you'd like. Maybe split the cost of the tires. But don't pass on it. Good coaches that age can be difficult to find.
1997 37' HR Endeavor, 275hp Cat, Freightliner
03 CR-V Blue Ox, Ready Brake