Dutch auctions are not susceptible to market manipulation. They cannot be shill bid. If perfect market efficiency were possible, the sale price of a Dutch Auction would represent the first intersection between the lowest price a seller is willing to sell an item for with the highest price a buyer is willing to buy it for. This is why a Dutch auction represents the best method for collectors to sell to collectors. So bid with confidence, knowing that you are getting an item you want for your collection at a fair market price.