Yes and no. A lot of the cars that go at auction are reposessed. I've seen a ton of them that were really fucked up by the previous owner knowing that the vehicle was going to be taken. I strongly recommend bringing someone with you that knows a lot more about cars than you do. Have them look for signs of abuse, crashes, water in the oil and other potential huge problems. Also, it is a good idea to buy into the CarFax thing so you can look up VIN numbers on a smartphone for details of wrecks, salvage or other records pertaining to the car. Finally, get set up with a Blue Book so you can gauge the average prices for the car in your area. Based on the going prices and the status of the car, set yourself a maximum price you're willing to pay for it at auction. Don't go over it.
I'd look to sell a car from auction for 95% of Blue Book for a quicker sale. Consider dropping to 90% after a couple weeks if no takers. Set your purchase price where you want it to give you enough money back after doing all the paperwork, a quick service and the legwork getting the car sold.
Most auctions have a preview the day before, or very early the day of the auction. Go there at that time and do your research. Most auctions will start with the high priced cars first. They will go for near retail price mostly, but eventually the people looking for those types of cars will be done and the price of them will drop off. I've seen $40,000 cars go for $12,000 range at this point. This is where you can make serious bank if you have the funds up front to do it. After those cars, they start into lower priced stuff. If you're not into the luxury car market, you could probably sleep through the first 90 minutes of the auction.
