Most first-time merch sellers price the same way: pick a number that "feels right," compare it to a couple of competitor stores, and hope it covers costs. It's a reasonable instinct, and it's also how a lot of sellers end up working hard to lose money per order.
Here's the math that actually matters.
Start from wholesale cost, not sale price. Every product has a wholesale cost — what the print provider charges to make and ship it. Your margin is the difference between what the customer pays and that wholesale cost. That margin, not the sale price, is what the platform fee is calculated against, and it's what you take home.
The fee scales with how much you've sold, not what you're selling. On UpMerQ specifically: 0% while your store is building its first $250 in cumulative sales, 20% of margin from $250 to $5,000, and 15% once you've crossed $5,000 — a rate drop that rewards stores with real traction. There's no monthly subscription sitting on top of that.
A margin guardrail protects you from yourself. It's easy to set a price that looks competitive but barely clears the wholesale cost — especially once a fee comes out of that thin margin too. A guardrail that keeps your sale price at a healthy multiple of wholesale cost (roughly 1.8x) exists so a "great deal" price doesn't quietly become a break-even, or losing, one.
A quick example. Say a shirt costs $9 wholesale. At a $22 sale price, your margin is $13. Below the $250 threshold, that $13 is yours. Above it, at the 20% tier, the platform takes $2.60 and you keep $10.40 — still a healthy margin, because the sale price was never set by guesswork in the first place.
Price from the wholesale number up, not from a competitor's storefront down. The fee tiers and the guardrail are there to make sure the price you land on can actually sustain the business you're building.