# Price the whole stack

Lesson 2 of [Compare AI voice agent vendors before you buy](https://voiceagents.fyi/academy/compare-ai-voice-agent-vendors.md), 15 minutes.

A rate per minute is one number. Your bill is a stack. The five parts 1. The platform fee, which runs the agent, the call logic and the dashboard. 2. The language model. 3. Speech-to-text. 4. Text-to-speech. 5. Telephony, which carries the call and owns the number. A speech-to-speech model can repla…

The rest of this lesson is for learners enrolled in the course. [See how Compare AI voice agent vendors before you buy works](https://voiceagents.fyi/academy/compare-ai-voice-agent-vendors.md).

Also on the [web page](https://voiceagents.fyi/academy/compare-ai-voice-agent-vendors/price-the-whole-stack).