If your opponent would bid, say, $500, but it's currently at $400, they might only put in a bid for $425, and if you bid more than that right before it ends you can get it for $430. While if you'd bid $475, then your opponent might have bid it up to $480, causing you to end up paying more.
Is anyone actually irrational in this scenario? I suppose anyone not using sniping tools and also not bidding their highest price is, or at least they could get a strict improvement by doing so. Given that other players aren't rational, the whole assumptions break down.
For example, foreign jewellery on which you are unfamiliar with the hallmarks. You don't mind paying $200 for it if it is silver, but is it ?
Of course, rationally, for the raison you gave, you should not use that, but conversely if you are familiar with a certain type of popular auction you start to see some patterns. An object that breaks it is either a bargain, a fraud or you were simply early.
For example, silver never goes for less than scrap and genuine auction never really shoot way over boot sale value.
Or maybe I rationalised my irrationality :-)
Personally I'm more than happy losing a bid if I make someone else suffer winner's curse just because they are blinded by escalation of commitment and a long list of other biases.
One of my favourite speeches touching on the subject: The Psychology of Human Misjudgement - Charlie Munger Full Speech
bit about auctions is at 59:30 https://youtu.be/pqzcCfUglws?t=59m30s text https://buffettmungerwisdom.files.wordpress.com/2013/01/mung...
For this reason I find the last paragraph of the article confusing:
> Hermann and Dorothea went on to be a bestseller, earning tens of thousands of talers for Vieweg and nary a penny more for poor Goethe.
But Moldovanu & Tietzel (1998) [0] do report in their article that "Vieweg offered exactly that sum [1000 thalers]". So there it is!
[0]: https://www.econ2.uni-bonn.de/pdf/papers/goethes_second.pdf