What buyer's premium actually costs you, and why most "auction deals" aren't

Say you win a 10 oz silver bar at auction for $740. Spot's sitting around $75/oz that morning (call it $750 of melt), so you've just bought ten ounces of silver for ten dollars under melt. The same bar runs about $810 delivered at a typical online dealer. You've beaten the dealer by $70 from your couch, in your pajamas, feeling clever.

You haven't. You've overpaid by about eighty bucks, because you forgot to count the buyer's premium.

That's the whole lesson, and it cuts both ways. Run the all-in math before you bid and auctions are the cheapest metal you'll find anywhere. Skip it and you'll spend a year paying retail with extra steps and calling it a deal. The auction isn't the trap. The un-run math is.

(Spot won't be $75 by the time you read this. Plug in whatever it is. The math works the same at any price.)

What the buyer's premium actually is

It's a percentage the auction house adds to your winning bid. You "win" at $740. You pay $740 plus their cut. It's usually somewhere between 15% and 25%, and it's calculated on the hammer price, the number that feels like what you paid, even though it isn't.

None of this is a trick. The premium is published in the terms, it's the same for everyone in the room, and it's how the house gets paid for running the sale. It's a normal, known cost. It just sits outside the rough melt math you're doing in your head while the hammer climbs, so newcomers forget to add it, and then it lands at checkout, after the adrenaline's worn off.

It's also rarely the only add-on. Bid through a live-bidding platform and it usually stacks its own fee on top of the house's. And the premium itself assumes you're not paying by credit card: a card typically tacks on a few percent more (the house passing along its processing cost), while an e-transfer, wire, or cash usually avoids it. How you pay is part of your all-in too. Then shipping and insurance. All published, all normal, all easy to leave out of the quick math.

The deal that wasn't

Here's that $740 bar, all the way to your door, at an 18% premium:

Hammer: $740.00. Buyer's premium (18%): + $133.20. Shipping, small heavy insured package: + $20.00. All-in: $893.20.

The dealer wanted $810 delivered. You'd pay $893.20, about $83 more than just buying the thing outright. Against melt, that's $143 over $750, a 19% markup over melt.

The $70 "savings" on the hammer was never real. Not because anyone hid anything (it's all right there in the terms), but because it's easy to anchor on the hammer and never run the number that matters.

Why the best lots sell below spot

Run it backwards. To beat the dealer's $810 delivered, your all-in has to land under $810. Pull out the $20 of shipping and you've got $790 left for hammer-plus-premium. Divide by 1.18 and your hammer has to come in at $669 or less.

$669 is eighty-one dollars under the bar's melt value.

Read that twice. To beat a dealer selling at a modest markup, you often have to win the metal for less than it's worth as raw melt. The premium absorbs the whole apparent discount and then some, so the hammer has to start underwater just to surface at break-even.

Here's the part that should make you want to bid, not avoid it. Almost nobody runs this math. Most people in a 600-lot sale glance at a hammer sitting under melt, figure the deal's either obvious or already gone, and move on. So the genuinely under-melt lots, the ones that actually beat a dealer all-in, sit there in plain sight, waiting for the one bidder who set a real all-in max. In a sale that big nobody's watching all 600 lots, and thin attention is exactly where below-melt hammers happen.

The difficulty isn't the deterrent. It's the moat. The math being annoying is the only reason these deals survive long enough for a disciplined buyer to win them.

How to bid like the buyer who wins those lots

Decide your all-in ceiling, then work backwards to a hammer max. Don't bid against the hammer number. Bid against your delivered ceiling. If that ceiling is $810, the premium's 18%, and shipping's $20, your hammer max is $669. Bid that. Not $670.

Know the premium before the sale starts. It's in the terms, it varies by house, and the live-bidding platform may add its own on top. Check what payment method costs least while you're there.

Count every add-on, not just the premium. Shipping, insurance, card surcharge. Small individually, brutal together.

Then hold your number when the hammer passes it. The pace is fast and the energy's contagious, and it's genuinely easy to lose track of your max in the moment, which is the whole reason you set it before the lot comes up, when you're calm and the calculator's open. Set it, hold it, let the lot go if it climbs past. There's always another auction.

Doing this backwards-math on one lot takes a minute. Doing it on every bullion lot in a 600-lot catalog (weight, purity, current spot, the house's exact premium, shipping) is a few hours of spreadsheet grind that, realistically, nobody does. Which is why the deals are there in the first place. That grind is the whole reason BullionBidder exists: it runs the all-in math across an entire catalog and flags the few lots that actually beat retail delivered, so you're not doing it by hand.

The only question that matters

Next time you see a bullion lot sitting under melt and your gut says deal, run the one number most of the room won't bother with: your all-in, delivered, premium and all. Does it beat what a dealer would charge you? You don't have to do it in your head. Quick Check runs exactly that on a single lot (hammer, premium, and shipping against the dealer price, in a few seconds) so you can tell whether the lot you're eyeing is the real thing or just another hammer under melt that isn't.

Answer that before the hammer falls and auctions will hand you the best prices in the hobby. Skip it, and you're just paying retail the hard way. The math is the whole difference, and almost nobody does it. That's the opportunity.