How it works
The Bid Checker answers one question: “At this bid, is this actually a good deal?” Here’s how to use it and the math behind it.
1. Find the real market price
Paste the item name from Nellis and tap Find on Amazon, Price history (CamelCamelCamel), or Compare prices (Google Shopping). Use the genuine current retail — not the inflated “MSRP” Nellis sometimes lists. Enter that number as the Real Market Price.
2. Read your bid targets
The tool instantly suggests three ceilings, each calculated so your all-in cost lands at a target fraction of retail:
- 🔥 Great deal — all-in around 50% of retail.
- ⚡ Good deal — all-in around 65% of retail.
- ⚠️ Max bid — all-in around 80% of retail. Above this you’re barely saving versus just buying it new.
Tap any target to load it as your bid, or type a custom amount to test.
3. Check the grade and breakdown
You’ll see the deal graded from GREAT DEAL down to OVERPAYING, plus the full cost breakdown.
The math
Auction houses charge a buyer’s premium (a percentage added to your winning bid) and then sales tax on top. The formula:
All-in = Bid + (Bid × Premium%) + ((Bid + Premium) × Tax%)
Example at the Nellis defaults (15% premium, 8.375% tax) on a $100 bid:
- Buyer’s premium:
$100 × 15% = $15.00 - Sales tax:
($100 + $15) × 8.375% = $9.63 - All-in out the door: $124.63
So a $100 bid really costs you about $125. If that item retails for $250, you’re saving 50% all-in — a great deal. If it retails for $140, you’re barely ahead.
Using it for other auction houses
Open ⚙️ Fee settings and change the buyer’s premium and tax to match any auction house. Hit Reset to Nellis defaults to snap back to 15% / 8.375%.
Pro tip: the only number that should ever beat retail in your head is the all-in figure. The hammer price is a vanity number — fees are real money.