I accumulated losing bids of $55,000! Lol. That's money that I've never even seen in my life - but just goes to show what a fight to the death this auction was. Lord have mercy! I tried and I tried, got close to winning on some items, but invariably, they would end up just above my absolute limit or else to an amount that I just didn't feel was appropriate for what it was.
As to your question, I've wondered about that too. My guess was this: I happen to know that many interested parties were friends with Greg Jein, had been to his house, seen his collection in the flesh. I can imagine that some of these guys bid liberally, maybe not even always to GET the item, but to drive prices up some for the benefit of Jein's family. I mean, if they weren't before, they are multimillionaires today. (But that whole thing may be a bit of a conspiracy theory, and I intend no disrepect by speculating here...)
Having said that, it is INSANE that e.g. an Ezri Dax costume would go for 30,000 dollars. THIRTY THOUSAND! Where, mind you, similar items (Starfleet uniform costume from a spin-off show, not TOS, character other than the captain or highly-popular secondary such as Seven of Nine) typically go for anywhere between 5,000 and 8,000 or so. In the recent Comisar collection on Heritage, costumes worn by Shatner, Nimoy, etc. went for less than that.
EDIT: Can I ask (since it's done anyway) what items you were interested in and what your preception was of the bidding process?