The winner may end up paying well under his valuation and thus the seller does not receive the maximum price. However, in the Dutch system, if the bidder with the highest interest really wants an item, he cannot afford to wait too long to enter his bid. That means he might bid at or near his highest valuation. Type Rules English, or ascending-price. Seller announces reserve price or some low opening bid.
Bidding increases progressively until demand falls.
Winning bidder pays highest valuation. Bidder may re-assess evaluation during auction. Dutch, or descending-price. Seller announces very high opening bid. Bid is lowered progressively until demand rises to match supply.