Four numbers decide whether this is a business or an expensive hobby. This is where you find out which one you have... before you spend a dollar.
Freight and duty are estimated as a percentage of your unit cost, because that is how they actually scale... a heavier, pricier product costs more to move and gets taxed harder. Overseas assumes 18%, nearshore 9%, domestic 3%. Real freight depends on weight, volume, season and your product's tariff code, so treat this as a placeholder until a freight forwarder gives you a real number.
Payment fees are estimated at 2.9% of the sale plus 30 cents, the standard published card rate most new brands land on.
Discounts and returns come off the top of your price, because a promo code and a refund both cost you revenue you already counted.
What this does not include: your ads, your software, your packaging design, your sample rounds, your time. Those all come out of what's left. That is why what's left has to be big.
The bands. Under 40% is thin... you will struggle to buy a customer profitably. 40 to 59% is workable but disciplined. 60% and up is where paid acquisition starts to make sense. These are rules of thumb for physical consumer products, not laws.
Got your price roughed out? Build the real cost behind it in The Three Buckets, then set the price in The Margin Dial. Finding who makes it? The Supplier Scorecard.