Started New Project - Concerns over new pricing model

We have just started a new project for the business to support our internal management and allowing our clients to login and perform actions.

In terms of comms we rely heavily on Freshdesk and for accounts we use Xero. There will be quite a lot of API traffic with these 2 external systems so that users can view comms and transactions are synced between the 2 systems.

My concern is that the new pricing model is going to make this a very expensive solution, but I don’t want to spend months of development cost building it only to find this is the case.

Are there any recommended approaches now that workload units are going to affect API calls and Webhooks, specially as Xero webhook returns changes/additions to every transaction?