Also known as a Preview. A shill is a bidder at an auction like you with one exception. This person has no intention of buying anything. His sole purpose is to drive the bidding as high as he can without having the final bid. Shills work for the auctioneers who receive a commission on the total dollar amount that is sold.
Shills are illegal.
If you see some one who bids a lot but never buys anything watch out he may be a shill. Stay away from this auction. To be fair to all the honest auctioneers It is very rare to find a situation like this. Las Vegas Hotels. The guaranteed lowest rates.