The kind you need a dealers license for that is.

I'm in the market for a new vehicle (new to me) and my father has a friend who has a dealer's license. My dad is telling me how I should go to the auction to buy a vehicle since I will be paying cash. I have $7k to spend. I'd REALLY like to get some type of Fullsize chevy/ford 4x4 w/under 100k on it, and newer than 98. I know it's asking a lot, but is it possible? I always here about people saying they got these KILLER deals at auctions. Any of you have experience there? I don't really want hearsay because that's what I'm currently basing my opinion off of. Thanks in advance