Sourcing cost tracking for online resellers

The idea

Resellers buy inventory in bulk: a $47 Goodwill receipt covering fourteen items, three of which sell this year, five next year, and six never. At tax time, Schedule C wants cost of goods sold for the items that actually sold, and nobody can reconstruct that from a shoebox of receipts and an eBay sales report. The result is guessed numbers and genuine audit exposure for people now receiving 1099-Ks at low thresholds.

Crosslisting tools like Vendoo and List Perfectly own the listing workflow but ignore cost accounting entirely, which is the actual painful and legally consequential part. A tool that does one thing, tying receipts to items and items to sales, slots in beside whatever they already use rather than competing with it.

Who pays

The reseller pays $10/month, free up to 50 items so the death pile gets loaded in before the paywall matters. The buyer is a part-time or full-time flipper doing $10k to $100k a year who just received a 1099-K and got scared. Signups spike hard in January; distribution is reseller YouTube (a large, sponsorship-friendly niche), r/Flipping, and SEO on reseller tax questions, which have huge search volume and weak answers.

MVP scope

• Haul entry with receipt photo and total
• Cost allocation across items, even or manual, with sum validation
• Mark-sold flow capturing platform, fees, and shipping for per-item profit
• Year-scoped Schedule-C-ready CSV export (COGS on sold items, fees, shipping)
• Skip for v1: platform API imports, crosslisting, mileage tracking, sales-tax handling, and barcode scanning

Build HaulLedger, a cost-of-goods tracker for online resellers. Stack: Next.js (App Router, PWA-friendly since entry happens on phones in car parks), Supabase (Postgres, auth, storage), Stripe for subscriptions.

Core flow: after a sourcing trip the reseller creates a haul: source (Goodwill, estate sale, bins), date, total receipt amount, and a photo of the receipt stored in Supabase Storage. They then add items to the haul (title, optional photo) and allocate the haul cost across them, either evenly with one tap or manually per item; the app enforces that allocations sum to the receipt total. Items sit in inventory (the death pile) until marked sold, at which point the reseller enters sale price, platform (eBay, Poshmark, Mercari), fees, and shipping cost, and the app computes true profit per item.

Pages: haul list, haul detail with allocation UI, inventory list with age-of-item, sold items with profit column, reports, settings, billing. Reports page shows COGS for items sold in a chosen year (not items bought, the distinction matters for Schedule C) plus totals for fees and shipping, exportable as CSV.

Non-obvious details: an item can be marked as personal-use or donated, which excludes it from COGS correctly; unallocated remainder on a haul is tracked visibly so nothing is silently lost.

Pricing: free up to 50 items, then $10/month unlimited.