i totally see what you are saying- but as a buyer, you then either, bid on a name, and get it (you give money, you get domain) or, the seller backs out (you still get $)- if you bid more than you felt a name was worth- you either get the name, or get money for not getting the name- regardless of what you bid you walk away with something. doesnt matter if you bid 10 grand on a 500.00 site- you are the side of all positive possible endings. but you are ultimatly in control- if you did bid that much, and won, your still not a loser with a cheap domain that you paid a ton for,because you were in control of your bids. you had the choice.
as the seller- you bid 50 bucks on a 500.00 domain, and no one else is bidding- well guess what, i take a loss no matter what, dont i- either i sell at 50- or i pay you so i can keep my domain.
see what i mean? kinda seems a little heavy handed on one side this way. and with that being said, i do not think you will say any big names in there- you'll some decent ones- some usable ones- and some you can surely develope- but the very expensive stuff....... i cant imagine anyone would do that with that much money at stake for the seller.
how to get around this i dont know exactly- i would think a seller who wants to make a sale, would reserve it small.... this is an auction after all, not an "offering" so it should start at way below the price- or dont enter your names at all......- but, there should be a little protection for the seller too- the lose/lose thing, ick :-(