There are 13 Vincents in the auction.
Perhaps the majority of bidders held off to see how that first one would sell.
A good friend of mine who buys and sells bakery equipment told me one of his rules for auction buying- if multiple items of one type are on offer, try to get the first one, it will be the cheapest. If the auction house offers to let the bidder have the rest at this price ( they often do on small stuff), then take the works.
He's learned that most bidders hold off as long as possible, always thinking things will go cheaper at the end. Almost every time it goes the other way!
Glen