# Estimate the real cost

Lesson 2 of [Evaluate a sandbox provider before you commit](https://agentsandboxes.fyi/academy/evaluate-an-agent-sandbox-provider.md), 15 minutes.

A low rate per hour does not always give a low bill. Providers meter in different units, and idle time, storage and egress change the total. Know the meter Ask each vendor what one billable unit is. Providers in this index bill per active CPU second, per 10 milliseconds of CPU time or per GB-RAM-sec…

The rest of this lesson is for learners enrolled in the course. [See how Evaluate a sandbox provider before you commit works](https://agentsandboxes.fyi/academy/evaluate-an-agent-sandbox-provider.md).

Also on the [web page](https://agentsandboxes.fyi/academy/evaluate-an-agent-sandbox-provider/estimate-the-real-cost).