I have spent lots of money at auctions over the years...
Usually I will set a price in my head, the bidding goes to that point..so others have had the same price idea that I have. Lots of times I will go Ohhhhh OOOKKKay I will go one more bid...and I will get it.. on those items I usually do real well.
Then there have been times when I have said "I WANT IT"...then I have at times gotten into trouble..and have overpaid...where I pay the price for my irrational exuberance when go to sell it. Generally it is a haircut and not a total loss. Which i have made up for in my next purchase.
Sometimes the bidding goes right by my price point even before I can get a bid in and then I usually say what am I missing with this one????
Then there are times when I get something for 1.5 and it turns out to be worth 5....those are the times I like...
THE GENERAL IDEA IS TO KNOW THE VALUE AND NOT TO CHASE.