Think about the increments for <50$ increases 1$ over hundred they may go 5 or 25$ depending how fast to a point where 50 or 100$ increments start. That is the auctioneers discretion what does. You maybe bidding on 10,000$ item, you are 9500$ bidder, some one else goes 10k. but yet you might get it for 10,500$ that is why they ask.
I've seen some stuff start at 50 cents and go for a thousand dollars or more! and the auctioneer's ask "what is it made of? gold?" or after it sells "got two more here on the back of the truck"
The wife just got a bunch of stuff at a local farm sale, nice Goodyear Service sign form the 20's no wing foot on it blue and white, cleaned up nice!!! nfs!