We have 3 plans we want to set up - each with the same structure.
Monthly SaaS $ + % of attributable GMV for the App
How should we go about setting that up and testing it.
We found a reference to the following: ""After creating a recurring application charge that's required for usage charge recurring_application_charge_id (and/or capped charge amounts) you can create usage charges as a percentage of sales. The price field on UsageCharge is not an integer as suggested in the property doc of the API i.e. you can use fractional amounts as with any other price / money fields."
Is this the recommended approach or is there a better approach?
Using UsageCharges is how you would be able to charge merchants based off something like GMV attributable to your application. You will be responsible for determining what the amount you will be charging in the usage charge, i.e. you will be responsible for determining (% * GMV).
You are correct the price field is of type MoneyInput which allows you to specify the amount in decimal form.
If you haven't already you can review this tutorial on creating usage based billing plans.