Shopify fees on one sale
On your own Shopify store the per-order cost is card processing. With Shopify Payments on the Basic plan that is 2.9% plus $0.30 of what the buyer pays.
Unlike Etsy, Amazon and TikTok Shop, Shopify takes no commission on the sale itself; you pay for the store and for card processing. That usually leaves more per order, but you bring your own traffic.
See the same order on each marketplace in the POD profit calculator.
Source: Shopify fee page. Shopify Payments online card rate on the Basic plan. Subscription not included per order.
Read the guide: How to price print on demand on Etsy, Amazon, TikTok Shop and Shopify
Questions
No. The Shopify plan is a fixed monthly cost, not a per-order fee, so it is left out of the receipt. Spread it over your monthly orders when you price.
Shopify adds its own transaction fee on top of that provider's fee when you do not use Shopify Payments. Check the rate for your plan on Shopify's pricing page.
Yes. Paid apps, themes and ads are separate. Add your ad cost per order in the profit calculator to see your real margin.