You know what a workflow costs in credits. The better question is whether those credits are buying the desired outcome - and where to spend fewer of them for the same result.
A collections call sounds like one task. As a workflow it's six execution steps: pull the account, classify the situation, have the conversation, check against policy, extract the commitment, write it back. Only one step - the conversation - is truly where better judgment converts into money.
On the HappyRobot platform, deterministic steps don't invoke a model at all. For the steps that do, you select the model per step, and can then A/B test alternatives to see which one actually earns its cost.
We break down these levers, and how they compound, in the blog post linked in comments.