You can place bids or set maximum bids (proxy bids) on any lots you wish to purchase. Some auction lots may have a buy it now (BIN) price. If you go through the buy it now process you will win the lot instantly.
Onsite Webcast Auctions:
You can set maximum bids (proxy bids) on any lots prior to the auction end date. On the auction end date, you can place online bids when a lot is being auctioned off by the auctioneer.