I think that's the best way, and eliminates the hassle of getting yourself started in a bid war. Just enter your max, and wait to see if you win it.
I agree with those who say prices would actually decrease if Ebay did this. I know that I would be a part of it. I am not interested in hanging around the computer bidding. I snipe. If you tell me that I cannot snipe an auction anymore, (either by banning sniping or having auction extensions), then I simply stop bidding. End of story. I would find other places to buy coins. The reason I snipe is that I don't want to get dragged into a bidding war. I wish to place a bid I am comfortable with, and either win it or not. I know myself and know I would try to justify "just one more bid". For the same reason I leave bids with the auctioneer most of the time for a live auction, and simply bid near the end of CNG auctions and not look until its over. Again, if Ebay did either of these things, I may bid every once in a while but my bidding would go down tremendously. This will have to have an affect on prices if others like me followed suit.
It still seems to me that prices would go up, due to all the psychological effects discussed above, but you make excellent points. If enough others agree with you, that might explain why eBay (which does survey its users frequently) has elected not to do things this way. After all, they've got a clear interest in maximizing total dollar volume.
Kind o' like the 'shot clock' rule in basketball. Makes things interesting, but the 'set it and forget it' guys ain't gonna like it........check that.....maybe they will as the price they're willing to pay has already been formulated in their minds.
I bet you would find if you had access to information Ebay does that a large amount of their buying population buys like I do. I believe that is the population they are afraid of scaring off. Remember, Ebay is not bulletproof, they always have to walk the line of making sure enough buyers are interested in their site. Buyers are the key, since they spend the money. Sellers gripe about Ebay, but most simply do not have the ability to sell the volume at the price without Ebay buyers. However, if the buyers get ticked off, and start going elsewhere, that literally is the end of Ebay auctions. Edit: I don't mean this as being arrogant or saying buyers are better than sellers. My point is that sellers will go to where the buyers are, since the buyers are spending the money. There are lots of sites with sellers and no buyers, and the sites do poorly. Of course good products and service are important, I just follow the money.