Most of them, to my knowledge, have the "bid on a lot, you're open to extended bidding on that lot" set-up. A few have the "bid on one, extended bid on all" program. I'm generally fine with most rules the AH's set-up - if not, I don't bid/participate.
To your question about being the only one bidding - that cuts both ways IMO. On one hand you got a good price (presumably), didn't get bid up and the item is yours. On the other, why didn't anyone else bid? And did I overpay, did everyone else see something I missed or is demand waning for that item.
Overall and as others have noted in previous threads, I think there are too many AH's. I can't keep track of who's who, what, when, etc - even with tools like Auction Report. Some have jacked up their shipping charges in addition to a higher BP (20% +) One of them is up to 22% now in addition to some fat s/h fees. The s/h fees aren't a big deal in the broad spectrum, just the principle and nickle/diming greed digs at me to some extent.
Factor in tax considerations for those in your state or claim to be and it usually means you're buried somewhere in on under-bidder list .. unless you really want that card badly, then you may have some buyers remorse afterwards
There have been threads on that - especially those with the huge sigh of relief when their "remorse after I hit the enter button" high bid made quickly and out of emotion was finally trumped by someone else
