I love those live auctions. Very exciting watching those. It's amazing the prices some items fetch with 1 picture and no description at all!
I posed the idea for using that and getting TNet to sponsor an auction of member submitted finds and such, but it was met with an extremely cold reception.
I think live internet auctions are a growing industry. To have people submit items for the auction and be able to comment on them and then link the item from live auctioneers to the forum would add a lot more credibility than a lot of the auctions. I'd imagine many items would turn into bidding wars.
Why not have no charge for sellers and charge a 15% (plus live auctioneer fees) to the buyer? Seller would have to pay shipping fees. (You can pass this to the buyer, but that may be a selling point, free shipping)
Most of those places charge 15, 20 or more % to the buyers and then sellers to list get charged 20% commission fee.
The buyer premium would cover the cost of the auction and more. There will be a lot of work to list the auction, make sure everyone gets paid and that everyone ships their items.