https://allstar-auctions.hibid.com/...-a-step-deck-1rnd48?q=2006+Reitnouer+Aluminum
The Buyers Premium is 12% on this auction and the total (bid price plus BP) will be subject to HST. This means every $100 bid will cost you $126.56 out the door. Of course, the HST you pay will be recoverable against HST that you charge on your services. Anyway, if the ceiling for your cash outlay is $12,0000, you shouldn't bid more than $9,481.67 ($12,000 / 1.2656).
BTW, I notice that the bid increments get pretty sizeable in the ballpark you're talking about. From a bid price of $1,000.01 - $2,500.00, the minimum increment is $100. From $2,500.01 - 10,000.00, the increment is $250 and then from $10,000.01 - 50,000.00 the increment jumps to $500. This might factor into your bidding strategy at the end.
Or maybe it will be like the auctions I've watched recently and the price will zoom well past any reasonable amount that I'd be willing to pay. For example, there was an auction with an angle block set that I was kinda interested in. I looked up the current price online (the pictures showed the details)--$39 USD. It sold for $60 CAD plus 10% buyers premium plus 13% HST for a total of $74.58. That seemed crazy to me especially when you consider that some of the pieces could have been dropped or otherwise abused!
It's like the pandemic has induced madness in online auctions!
Craig