What every buyer needs to understand is that any auction that is not absolute has a reserve. This is an amount set between the seller and the auctioneer. What I tell buyers is that they should bid to where they are comfortable and if the reserve is not met I will still take there offer to the seller and see if they will accept it.

In the case of our company, reserves are specified in the listing contract. They do not go up but may go down depending on the sellers thoughts as the auction progresses.

SECTION 40-6-20
(1) "Absolute auction" means the sale of real or personal property at auction whereby every item offered from the block is sold to the highest bidder without reserve and without the requirements of a minimum bid or other conditions which limit the sale other than to the highest bidder.  

The above definition is SC law regarding ABSOLUTE auctions and also tends to be federal law.