This is a huge consideration when buying a used car. If you buy privately or at an auction, you may well grab a great deal. An auction dealer has a reputation to maintain and should price their vehicles fairly, based on current market conditions.
Now is your chance to drive the price down. Large used car businesses work on the basis of sales volume. They will sell dozens, if not hundreds, of vehicles each week. Not only that, but individual employees often work on a commission basis, and will be eager to sell you a car. Use this to your advantage, and push for a price reduction and other extras to be thrown into the deal. Always be prepared to walk away; this demonstrates that you are serious. You may need to be tough, but the potential rewards are high.