Auction Arbitrage Overlay

Stop guessing. Know your number before you bid.

If you buy wholesale liquidation lots on B-Stock and resell on eBay or Facebook Marketplace, you know the risk: bid too high and your margin disappears before you ever touch the merchandise.

Auction Arbitrage Overlay fixes that. The moment you open a B-Stock Costco or Target auction listing, a sidebar appears — automatically — telling you the single most important number: the maximum you should bid to still hit your target profit.

What you see at a glance:
• Max Bid — the highest price you can pay and still make your margin, computed from the lot's total retail
• A sensitivity table — your max bid at every resale assumption from 5% to 100%
• How much more you can bid above the current bid — at a glance
• Per-unit and whole-lot retail, unit count, and condition — pulled straight from the listing

No spreadsheets. No tab-switching. No mental math mid-auction.

Analyze the Manifest — Know What's Actually in the Box
Most B-Stock lots ship with a full item manifest. Click "Analyze Manifest" and the overlay reads the entire manifest right on the page, totals the real extended retail, and surfaces the top items by retail value. For each one you get one-click research links — eBay, eBay Sold listings, and Facebook Marketplace — pre-filled with the item's keywords.

Tune it to your business:
• Set your target resale %, target profit, shipping, and platform fee
• Enter a lot's buyer's premium to fold it into the math
• Separate defaults for Costco and Target sellers
• An editable category-rate reference list you control

How it works:
1. Install the extension
2. Open any B-Stock Costco or Target auction listing
3. The overlay appears automatically — set your numbers, read your max bid, bid with confidence

No account. No login. No API keys. Everything runs locally in your browser.

Built by Ferrozen Holdings LLC — a real reselling operation that needed this tool and built it.