You can bid as many times as you like on the same item. The slide control is not switched off because you are ahead — it is only disabled when a custom amount is not a valid bid.
But if you are already the top bidder, bidding again only raises the price you will pay. Nobody has passed you, so there is nothing to answer.
Why people do it anyway
Two reasons, and neither works:
To look committed. The room sees a bid, not who placed it versus who placed the last one. Raising your own bid does not warn anybody off; it just moves the number you owe.
To protect against a last-second bid. This is the real worry, and the answer is a maximum bid rather than a higher bid.
What to do instead
Set a maximum. You name the most you will pay, and Metzee bids for you — the smallest step that keeps you on top, never more, and never past your number.
So if nobody challenges you, you pay the current price. If somebody does, your ceiling answers them one step at a time without you being there. It is strictly better than bidding yourself up, and nobody can see the number. What a maximum bid is
One thing to know: a maximum can be raised but never lowered, because it has already done its bidding on your behalf.
The thing that makes this safe anyway
On a standard auction, a bid in the final ten seconds pushes the clock back to ten seconds. You cannot be sniped at zero, so "I should bid higher now in case somebody sneaks in" is solving a problem the format already solved. The last ten seconds
What you genuinely cannot bid on
Three refusals, each with its own message:
- Your own item —
You can’t bid on your own item - A store you work for —
You work at this store, so you can’t bid on its items. A team member bidding on their own store is shill bidding, with the reserve and the other bids in front of them. - A store that has blocked you, or one that is not taking bids right now.
Honest limit of this page
Whether the server refuses a bid from the current top bidder outright, rather than simply accepting a higher one, is decided inside the database function that places bids — which is not in the application code anyone here can read. What is certain is the part that matters to you: if you are winning, another bid from you can only cost you more.
More: how bidding works, what does outbid mean, how to place a bid.