How to Price Items for Resale: The Accountant’s Method

Most reselling advice tells you to triple your cost, or “keystone” it (double it), and move on. Here’s why that quietly loses you money and how to price the way an accountant would, so the margin you think you’re making is the margin you actually keep.

Quick example to show the problem. You buy a jacket for $25 and keystone it to $50. Feels like a tidy $25 profit  50% margin, right? Now subtract the real costs: a 20% platform fee ($10), the shipping label ($8), packaging ($1.50), and the gas to source it ($2). Your actual profit is $3.50 a 7% margin, not 50%. That gap is what pricing off a cost multiple hides.

Step 1: Know your true cost (not just what you paid)

The number most resellers price from is what they paid for the item. That’s only the first line. Your true cost is everything you spend to turn that item into cash:

• The item itself (your cost of goods sold)
• Sourcing costs — mileage or gas to thrift, sourcing app fees
• Outbound shipping — the label, if you cover it
• Packaging — mailers, boxes, tape, tissue
• Platform and processing fees — the 5–20% the marketplace takes
• Ad spend — promoted listings, if you use them

Group these into two buckets, because they behave differently when you price: fixed costs (item, sourcing, shipping, packaging, they don’t change with your price) and percentage costs (fees and ad spend, they rise with your price). That distinction is the whole trick to pricing correctly.

Step 2: Markup vs margin — the mistake that kills profit

This is the single most common pricing error, and fixing it changes everything.

• Markup is profit as a percentage of your cost.
• Margin is profit as a percentage of your selling price.

They are not the same number, and the difference is large:

So when someone says “keystone gives you 50%,” they mean 50% markup, which is only a 33% margin  and that’s before fees and shipping. The “3x rule” sounds like a 67% margin, but knock off a 20% fee and your shipping costs and it can land closer to 40%. Price off margin, the money you actually keep, not a cost multiple.

Step 3: Decide your target margin

Pick the net margin you want to keep after every cost. For reselling, a healthy net margin is often 20–40%, depending on item value and how fast it sells. Cheap, slow items need a higher margin to be worth your time; high-value, fast-moving items can work on less.

One caution: aim for net margin (after fees and all costs), not gross. A 50% gross margin that ignores a 20% fee, shipping, and packaging can leave you with almost nothing exactly the jacket example above.

Step 4: Price backward from your margin and fees

Here’s the accountant’s move. Instead of marking up from cost and hoping, you solve for the price that delivers your target margin after the fee. The formula:

Price = (Fixed costs + fixed fee) ÷ (1 − fee rate − target margin)

Where fixed costs are your item + shipping + packaging + sourcing, the fee rate and any fixed fee are the platform’s, and everything is in decimals (a 20% fee is 0.20).

Worked example. That jacket again: item $25 + gas $2 + shipping $8 + packaging $1.50 = $36.50 fixed costs. Selling on a platform with a 20% fee and no fixed fee, you want a 30% net margin.

Price = $36.50 ÷ (1 − 0.20 − 0.30) = $36.50 ÷ 0.50 = $73.00

Check it: the 20% fee on $73 is $14.60, leaving $58.40, minus your $36.50 costs = $21.90 profit — exactly 30% of $73. To actually keep 30%, you needed to list at $73, not $50. That’s the difference between guessing and pricing.

The shortcut: you don’t have to do the algebra. Open the calculator for your platform, enter your costs, and use the target-profit field it solves for the exact list price that hits your goal, fees and all. The formula is what’s happening under the hood.

Step 5: Sanity-check against the market and your floor

Your formula price is the minimum that meets your goal, now reality-check it two ways:

• Comps. Search sold listings for the same item. If your formula says $73 but the item reliably sells for $45, the item was a poor buy, or you sell at a thinner margin, or you don’t buy it again. The market caps your price; the formula sets your target.
• Break-even. Know the price below which you lose money, your fixed costs plus the fee at that price. Never list under it. The break-even calculator gives you this floor in seconds, and every fee calculator shows it too.

If the market price sits comfortably above your break-even and near your target, it’s a good buy. If it sits below break-even, walk away, no amount of clever pricing fixes a bad purchase.

The pricing cheat sheet

• Find true cost = item + sourcing + shipping + packaging (your fixed costs).
• Price = (fixed costs + fixed fee) ÷ (1 − fee rate − target margin).
• Margin = profit ÷ price. Markup = profit ÷ cost. Always price on margin.
• Floor = break-even. Ceiling = what the market pays. Target sits between.

Common pricing mistakes to avoid

• Pricing off cost alone and ignoring the 5–20% the platform takes.
• Confusing markup with margin — a 50% markup is a 33% margin.
• Forgetting shipping and packaging, which can be $8–$12 a sale.
• Racing to the bottom to match the cheapest listing instead of pricing for profit.
• Not valuing your time — if an item nets $3 after an hour of work, it’s a hobby, not a business.
• Ignoring fees that vary — international surcharges, ad rates, and minimum fees all change the math.