Why Many Resellers Underestimate Their Costs
One of the most common mistakes new resellers make is calculating profit as simply: Sale Price − Purchase Cost = Profit. This oversimplification leads to disappointing results and, in many cases, selling at an actual loss without realizing it.
True profit margin accounting means capturing every dollar that leaves your pocket in the process of buying, prepping, listing, and shipping an item. Only then can you make smart decisions about what to buy and how to price it.
The Full Cost Formula for Resellers
Here's the complete cost breakdown you should apply to every item:
- Cost of Goods (COG): What you paid for the item, including your share of any bulk purchase.
- Inbound Shipping/Freight: The cost to get the item to you from your supplier.
- Prep & Cleaning: Time or money spent cleaning, testing, or repackaging the item.
- Platform Listing Fees: Some platforms charge per listing or monthly fees.
- Platform Selling Fees: The percentage taken from your sale (eBay, Amazon, Poshmark, etc.).
- Payment Processing Fees: PayPal, Stripe, or built-in processors typically charge ~2.9% + $0.30.
- Outbound Shipping Cost: What it costs you to ship the item to the buyer (if not charged separately).
- Packaging Materials: Boxes, bubble wrap, tape, poly mailers — these add up.
- Returns & Refunds: Budget a small percentage for returns across your total inventory.
- Your Time: Optional to include, but critical for evaluating whether your business is worth running.
A Real-World Example
Let's work through an example. You buy a liquidation lot of kitchen items and estimate one blender cost you $8 from the lot. You list it on eBay for $35 with free shipping.
| Cost Item | Amount |
|---|---|
| Cost of goods | $8.00 |
| Inbound freight (allocated) | $1.50 |
| eBay final value fee (12.9%) | $4.52 |
| PayPal/payment processing | $1.32 |
| Outbound shipping (USPS) | $7.80 |
| Packaging materials | $0.75 |
| Total Costs | $23.89 |
| Net Profit | $11.11 |
| Profit Margin | ~31.7% |
A 31% margin is solid. But notice that without accounting for shipping and fees, you might have mistakenly thought your profit was $27 instead of $11.
What Is a Good Profit Margin for Resellers?
Target margins vary by product type and model:
- 30%+ net margin: Excellent — pursue these deals actively.
- 20–29% net margin: Good — viable if item moves quickly.
- 10–19% net margin: Low — only worthwhile on high-ticket or fast-moving items.
- Under 10% net margin: Risky — small errors eat all profit. Avoid unless volume is very high.
Using a Break-Even Price
Before listing, calculate your break-even price — the minimum sale price that covers all your costs. Price below this and you lose money. A good rule is to set your listing price at least 40–50% above your break-even to allow for negotiation, promotions, and unexpected costs.
Tools to Help Track Costs
- eBay Fee Calculator: Available on sites like salecalc.com for quick fee estimates.
- Google Sheets or Excel: Build your own cost tracking spreadsheet for every item or lot.
- Inventory management apps: Tools like Seller365 or InventoryLab can automate cost tracking at scale.
Final Thoughts
Knowing your true profit margin is the foundation of a sustainable reselling business. Take the time to build a cost-tracking habit from your very first sale. The resellers who scale profitably are almost always the ones who know their numbers inside and out.