If you dream about an auction, pay attention to the objects that are being sold. What do they represent to you?
If you are doing the bidding in your dream, do you bid too low or too high? Did you pay more than your purchase was worth? These things could be a sign of whether your goals in life are realistic.
What things were you bidding on? The more you paid the more these objective representations will mean to you.
If your own possessions are being auctioned of in your dream, it could mean that you feel parts of your life are been taken away from you, or given away too cheaply?