It ain't by much, but we're a tiny bit cheaper than Stripe when you consider how much they charge for Billing (.7% for them vs .65% for us). And pretty much every Stripe integration uses Stripe Billing (unless they pair with a 3rd part billing SaaS)
Isn't Stripe Billing only for subscriptions?
To only pay Stripe 2.9% + $.30 they'd need to only use Stripe just for charges, and either build their own billing engine (usually poor use of time) or use a 3rd party SaaS.
As we approach Black Friday in the US, I'm thinking of the giant volume of e-commerce transactions that are not subscriptions (or usage-based), and of which Stripe gets a cut. It sounds like you are not angling for that part of the market?