Back in the 80's and 90's me & my business partner at the time went to a lot of auctions, tender and private treaty sales around the country and quite often a lot of what we bought we already had a customer for it, over a few years we built up a good relationship with some of the auction houses and did some good deals where the cost of running an auction or tender sale would not be cost effective although moving the entire stock of 2 electrical wholesalers does take some movingI remember my grandfather telling me "all you need is two idiots for a good sale".
One I always remember was an auction in Stockport there was about 10 bundles of 15mm copper pipe listed in separate lots and two bidders took the price well above the trade price that the plumbers merchants next door were selling it for, add in the 10% buyers premium and they paid well over the trade price and rather than take the stand on offer on some extra lots they bid on each one and bid well over again
The thing with any auction is not being drawn in by that common auction disease Bidditis I've seen it quite often that a few people get it into their head that they must have the lot at any price and a bidding war starts