ResaleKit - Reseller Profit Calculator & Data Export

ResaleKit - Reseller Profit Calculator & Data Export Stop guessing your margins. Start knowing them. If you sell on multiple resale platforms, you already know the math problem. Every platform takes a different cut — Poshmark's 20% commission, eBay's 13.25% final value fee, Mercari's 10% plus processing, Depop's payment fees. You list an item at $35, and your actual take-home is different on every single platform. Most sellers figure this out after the sale. That's backwards. ResaleKit puts the numbers in front of you before you list. WHY CROSS-PLATFORM SELLING IS SO HARD TO GET RIGHT Each resale marketplace has its own fee structure, and none of them make it easy to compare: - Poshmark charges 20% on sales $15 and above, but a flat $2.95 on sales under $15 - eBay takes 13.25% plus $0.30 per order - Mercari charges 10% seller fee plus 2.9% and $0.50 in payment processing - Depop removed their seller fee but still charges 3.3% plus $0.45 in payment processing Most resellers either ignore the differences entirely or maintain a messy spreadsheet that's always out of date. The result: you might be listing on the wrong platform for certain price points, leaving money on the table every single day. ResaleKit solves this with three tools built directly into your browser. WHAT THIS EXTENSION DOES ResaleKit is a lightweight data toolkit that runs inside Chrome on the platforms you already use. No spreadsheets, no formulas, no switching between tabs to do math. Here's what you get: Profit Calculator — Enter your item cost, selling price, and shipping. ResaleKit instantly calculates your net profit, ROI, and margin across all four platforms side by side. It highlights which platform gives you the highest take-home so you can list where it matters. Works on any webpage, even when you're not on a resale platform. Listing Export — Visit your closet, shop page, or search results on any supported platform. ResaleKit reads the listings on the page and lets you download them as a CSV or JSON file. Use it for inventory tracking, tax prep, or migrating listings between platforms. Sold Comps Research — Enter keywords for any item and ResaleKit searches completed/sold listings across eBay and Mercari automatically. It opens the search results, scrapes the sold prices, and shows you the average, median, and price range — all without you copying and pasting a single number. HOW IT WORKS 1. Install the extension and navigate to any supported platform 2. Click the floating "RK" button that appears in the corner of the page 3. Choose your tool — Calculator, Export, or Research 4. Get results instantly, right alongside your listings No account required. No login. No setup. The extension activates automatically when you visit a supported site. WHY A FLOATING PANEL INSTEAD OF A POPUP Standard Chrome extension popups close the moment you click outside them. That's a problem when you need to reference your listings while using the calculator, or when you want to keep research results visible while you adjust pricing. ResaleKit uses a slide-out panel that stays open while you browse. It sits on the right side of the page, out of the way but always accessible. Close it when you don't need it, open it when you do. PROFIT CALCULATOR DETAILS The calculator lets you select which platforms to compare. Toggle any combination of Poshmark, Depop, eBay, and Mercari. Enter three numbers: - Item cost (what you paid) - Selling price (what you plan to list it for) - Shipping cost (optional, defaults to $0) The results table shows each platform's total fees, your net profit, and ROI percentage. The platform with the highest profit is highlighted so you can spot it immediately. All calculations happen locally in your browser. Nothing is sent to any server. LISTING EXPORT DETAILS Navigate to a page with listings — your closet on Poshmark, search results on eBay, your shop on Mercari — and open the Export tool. ResaleKit scans the page and shows how many listings it found. Export options: - CSV — opens in Excel, Google Sheets, or any spreadsheet app - JSON — structured data for developers or advanced workflows Exported data includes title, price, listing URL, image URL, and sold status when available. SOLD COMPS RESEARCH DETAILS Price research opens sold/completed listing searches on eBay and Mercari in new tabs. The extension's content scripts automatically read the sold prices from those pages and report back to the panel. For each platform, you see: - Number of sold listings found - Average sold price - Median sold price - Price range (low to high) If you're on a listing page when you open the research tool, it auto-fills the item title as your search query. You can edit it before searching. REAL SCENARIOS WHERE THIS HELPS Sourcing at a thrift store: You find a pair of Nike Air Force 1s for $12. Before buying, you open ResaleKit's calculator on your phone browser. You enter $12 cost, $55 selling price. The calculator shows eBay nets you $36.52, Poshmark gives you $32.00, and Mercari lands at $33.43. You know exactly which platform to list on before you even buy the item. Cross-listing strategy: You have 200 items in your Poshmark closet. You export them all to CSV, sort by price, and realize 40 items are priced under $15 — where Poshmark's flat $2.95 fee actually costs more percentage-wise than eBay's 13.25%. You move those items to eBay and immediately improve your margins. Pricing a rare find: You picked up a vintage Levi's jacket and have no idea what it's worth. You search "vintage Levi's trucker jacket" in the research tool. eBay shows 45 sold listings averaging $78 with a median of $65. Mercari shows 12 sold at an average of $71. Now you have real data to price against, not guesswork. End-of-season clearance: You need to move winter inventory fast. You check comps for each item, set prices at the median sold price minus 10%, and calculate which platform still gives you positive ROI a…