If you price items based only on what you paid at the thrift store, you are leaving profit on the table or unknowingly selling at a loss. True cost per item covers the purchase price plus every dollar that went into getting that item sold. Getting this right is what separates resellers who scale from resellers who stay confused about where their money goes.
This guide walks through what goes into a complete cost of goods calculation, how to set up a tracking system you will actually use, and why accurate COGS matters for both your prices and your taxes. This is general information, not tax advice. For questions about your specific situation, consult a qualified tax professional.
What Actually Goes Into Your Cost Per Item
Most resellers count the purchase price and stop there. A complete cost of goods reselling calculation includes several more categories.
Purchase price. What you paid for the item at the thrift store, bins, estate sale, or wholesale lot. If you bought a bundle of ten items for $20, you need to allocate that cost across each item. A common method is equal allocation ($2 each), but you can also allocate by expected sale price if values vary widely.
Sourcing costs. Mileage to and from the sourcing location adds up quickly. The IRS standard mileage rate for 2026 applies here. Keep a simple log: date, destination, miles. Even short trips matter when you are sourcing three or four times a week.
Supplies. Poly mailers, tissue paper, tape, thank-you cards, and garment steamers are all part of cost of goods. Some resellers allocate supplies per item (divide monthly supply spend by items shipped). Others track it as a business overhead expense. Either method works, but be consistent.
Platform fees. Poshmark takes 20% on sales over $15. Depop, Mercari, eBay, and Grailed each have their own fee structures. These are typically subtracted from revenue to get net payout, but understanding them as a cost per sale helps you price more precisely. See the reseller net payout calculator for platform-by-platform fee math.
Shipping. If you offer free shipping and absorb the label cost, that comes out of your margin. Track label costs per item even if you are using platform-provided labels. Unexpected dimensional weight charges on boxes can quietly eat profit.
Time. This is the most debated one. Time is not deductible on your taxes the way expenses are, but tracking time per item helps you understand your effective hourly rate and decide where to focus. If a heavily researched piece takes 45 minutes to source, clean, photograph, list, and ship, you need the sale price to reflect that.
A Simple Spreadsheet System That Works
You do not need dedicated accounting software to start tracking COGS. A spreadsheet with consistent columns is enough for most resellers, especially when starting out. If you want a dedicated app later, check out the options in best bookkeeping apps for resellers.
Columns to include in your reseller COGS spreadsheet:
- SKU or item ID
- Item description (brief, searchable)
- Date sourced
- Sourcing location
- Purchase price
- Sourcing mileage (miles, not dollars — convert at tax time)
- Supplies allocated (flat rate or per-item)
- Platform listed on
- List price
- Sale price
- Platform fee (actual amount)
- Shipping cost paid
- Net payout (sale price minus platform fee and shipping)
- Gross profit (net payout minus purchase price)
- Net profit (gross profit minus supplies and sourcing allocated costs)
- Days to sell
One row per item. When an item sells, update the sale price, platform fee, and shipping columns. The profit columns calculate automatically if you set up formulas.
SKU tagging. A SKU is just a short code you write on a masking tape label and stick to the item. A simple format like `TP-0529-001` (thrift place, date, sequence) links the physical item to the spreadsheet row. This makes it fast to find the record when something sells. The reseller SKU system guide covers several approaches in detail.
Why COGS Matters for Pricing
Knowing your full cost per item lets you set a floor price below which you will not go. This protects you from accepting offers that feel fine but actually lose money once fees and supplies are counted.
A basic floor price formula:
`Floor price = (purchase price + supplies allocated + shipping estimate) / (1 – platform fee %)`
For example: item cost $4, supplies $0.50, shipping $5, sold on Poshmark (20% fee).
`Floor = ($4 + $0.50 + $5) / (1 – 0.20) = $9.50 / 0.80 = $11.88`
List below $11.88 and you are losing money before you even account for sourcing mileage or your time. The target profit margin for resellers post breaks down what margins to aim for across different price points and categories.
Once you know your floor, pricing decisions become faster. You set a target margin on top of the floor and adjust based on comps and demand.
Why Accurate COGS Matters for Taxes
When tax season arrives, your cost of goods sold reduces your taxable income. The IRS considers reselling a business activity once it is regular and profit-motivated, and the 1099-K threshold means many resellers now receive forms even at moderate volumes.
Documented COGS means you are not paying taxes on gross sales. Without records, you pay taxes on every dollar that came in. With records, you pay taxes only on actual profit.
For a deeper look at how 1099-Ks work and what resellers need to keep track of, read reseller taxes and the 1099-K. For the tax treatment of specific expense categories, consult a CPA or enrolled agent who works with self-employed sellers. This post is general information only.
Keeping Tracking Sustainable
The biggest reason resellers stop tracking COGS is that they try to catch up weeks or months later. Batch data entry from memory is slow and inaccurate.
Three habits that make tracking stick:
- Log purchase price and SKU at the sourcing location, before you leave. A phone note or voice memo works. Transfer to the spreadsheet at home.
- Update the sale row within 24 hours of a sale. Platform apps send notifications, so this is a natural trigger.
- Reconcile monthly. Pull the last 30 days of rows, check that every sold item has a complete record, and export or snapshot the sheet.
Staying current turns a month-end chore into a five-minute check. If you are listing at volume, the reseller daily routine shows how to build tracking into a consistent workflow without it taking over your day.
The goal is a system light enough that you keep using it, and detailed enough that it tells you whether the time you are spending on a category is actually worth it.
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Add to Chrome, FreeFrequently asked questions
COGS is everything you spend to acquire and prepare an item for sale: purchase price, supplies, shipping materials, and any directly allocated sourcing costs like mileage. It excludes general overhead such as internet or phone unless you allocate a business-use portion.
If you are selling as a business rather than occasional personal decluttering, the IRS expects you to report income and deductible expenses accurately. COGS is the primary deduction that reduces your taxable income from sales. Consult a tax professional for guidance on your specific situation.
The two most common methods are equal allocation (divide total cost by number of items) and value-based allocation (weight each item’s cost by its share of expected total sale value). Equal allocation is simpler. Value-based is more accurate when one item in the lot is worth significantly more than the others.
Time is not a tax-deductible expense, but tracking it reveals your effective hourly rate per category. If a category consistently takes long to source and list but sells for modest amounts, you can decide whether it is worth the opportunity cost. Think of time tracking as a business decision tool, not a tax tool.
Platform fees are a cost of selling, not a cost of goods in the strictest accounting sense. In practice, including them in your per-item cost calculation gives you a cleaner view of actual profit and helps you set accurate floor prices. Whether you classify them as COGS or selling expenses in your bookkeeping, track them consistently.
A spreadsheet (Google Sheets or Excel) is the most flexible starting point and costs nothing. As volume grows, dedicated bookkeeping apps built for resellers offer automatic fee imports and reporting. The [pricing page](https://quicklistai.org/pricing/) covers QuickListAI’s plans, which pair with your COGS system by cutting the time you spend on listing copy to near zero.