This comes from a support request here:

https://support.fivetran.com/hc/en-us/requests/162249

Because we don't do our trials within Zuora, in order to get pricing in the warehouse for product trials for accounts that are not yet Zuora paid customers we need to see the pricing on the product rate plan object. 

Zuora has a few ways in their API to return product_rate_plans & rate_plan_charges, unfortunately it looks like the data that you could get back varies depending on how you do it.In our Zuora API client, we use the API endpoint that lists all product_rate_plans for a given Product. This method returns a collection of PRPs, & each of those records then has a collection called productRatePlanCharges, & then each of those charges has an attribute called pricing, which includes single or tiered pricing data. 

https://www.zuora.com/developer/api-references/api/operation/GET_ProductRatePlans/