No cap vs a plan that upgrades itself.
BigCommerce ties each plan to a trailing twelve-month sales threshold: Core up to $30K, Growth up to $100K, and on Scale a monthly cap with an additional 0.9% on sales above it. Cross the line and the plan upgrades automatically, billed pro rata. Shopify has no revenue cap. You move up a plan for features and for a lower card rate, and you do it when you decide to.

