If you are going to hold a Live Auction, you really should hire a professional auctioneer. You may think that there’s not much to it – talk fast, tell some jokes, and point at people – but I can tell you that there is an enormous difference in the outcomes between an amateur and a pro.
Further, you don’t want just any professional auctioneer. Selling cattle, or heavy equipment, or used cars, is a very different skill set from managing a benefit-auction crowd, and inspiring them to support your cause to the greatest degree.
One of my favorite people in this business is Sherry Truhlar, who is herself an auctioneer, but who also does a LOT of training of auction chairs and event planners. She’s posted a pretty smart blog on how to evaluate auctioneers. It’s worth a read.