I have to chime in on one point:

Some people here (and elsewhere) have argued that they determine the highest price they want the item for, bid that amount and let the auction shake out where it will. If they win it, then great. If they do not, then fine also. As such shill bidding does not affect them, they claim.

I disagree. The buyer wants to buy the item as cheaply as possible (all other things equal). And so, if someone is shilling the bid up higher than it would be otherwise, you run the very real risk of buying the item for less than your maximum, but still higher than a shill-less auction would have been. If I was at a real live auction and the seller was watching me and bidding sometimes to bump up the price I would walk away. No way would I play that game. I consider that to be bidding against myself, which is the cardinal sin of all auction situations.

I still use eBay, but I only low-ball things anymore. I almost never win anything.

jim