Anyone who can afford $8k, can afford a bit more if you wait,or make a lower offer on a bit more expensive Bus. There are a lot of Buses out there, and as spring approaches, many more will be for sale in all the flavors for everyones tastes. There is no need to jump on anything in this market, just wait and watch. And while you wait and watch, learn as much as you can and plan for it.
That's just it! Also, it would be a painful thing to compromise on something now only to see your dream bus surface on Craigslist 6 months later for less money.
In my situation, it would be ideal to work a trade with someone if possible instead of being subject to a falling market. I think one of the best ways to come out is by trading, and the best trades help both parties.