You must have never been to an auction.
Standard procedures with all the major auction companies.
The deposit is required to make sure people don't bid on something and than split out the back door.
The deposit is 100% refundable if you don't purchase anything.
If you do purchase something the deposit can or will be applied to your check out bill.
Lou does not charge a registration fee just to come to the auction.
I will agree that I have seen it as common for arcade auctions, but not your everyday estate sales and auctions.
The only thing that I see as being a little tough is if you need to leave the auction early. The Downingtown auction was a little too busy to interrupt the collection of winning bids to get the deposit back until it was all over.

