I prefer a private party sale if at all possible. Past service and repair records are important, something a dealer won't have. Many of these "dealers" are not much more than turnaround lots for units they have purchased at auctions. Some can provide service, many have nothing more than a portable office. They seldom know anything about these rigs. We started by visiting lots of dealers and internet research to pick a make and model we liked. Once we had that it was a matter of locating a suitable unit. Depending on your budget it may not be possible to get the perfect color or options you want but you should be able to get real close. Research the manufacturer to see what options were available and if any recalls exist. We passed on one nice unit because it fell into the Cummins wrist pin recall. With a little effort you should begin to know more about a particular unit than the dealer will. Don't limit yourself to local units, do a nationwide search. These dealers travel all over the country to bid on these repo units, you can make a similar effort. It's a lot of money for a depreciating asset so a little effort now can save some money.