Write the number down
Set your maximum before bidding opens, with the premium, tax and transport already subtracted, and write it somewhere you will see it. The number is not a prediction of the final price. It is the point at which the purchase stops making sense for you, and it does not move because somebody else bid.
The price in front of you is not the value
Auctions work by making the current price feel like information. It is not. Two people bidding each other up tells you what those two people believe, which may be nothing at all about the vehicle. Your own research is the only valuation you control.
Bidding early buys you nothing
An early bid does not reserve a position; it advertises interest and gives other bidders a week to decide they want the lot. On a platform that extends the clock for late bids, there is no advantage in opening early and a measurable disadvantage in drawing attention.
If you have a watchlist, use it. Decide in the final hour.
Losing well
The discipline that matters is being willing to stop. There is another auction next week, with another vehicle that is nearly the same. Overpaying by three thousand because you spent a fortnight imagining yourself driving it is the single most expensive habit in this business.
From the auction floor
See how this works on a real lot.
Every listing carries its inspection report, its full specification and its bid history. Read one before you decide what it is worth to you.