How to set SaaS price for startups like loom?

We see many hot SaaS applications every day. like loom, MilkVideo, and Descript. But I'm curious how they set their prices and why does it make sense? 8$/month or 20$/m seems too cheap. If they use Google's speech to test API, probably they can not make any money. even if they have their own API, there are another costs like AWS and others cloud services.

Hey, see if you find some useful reads here: https://www.gorelay.co/tag/pricing

There are interviews and conversations with SaaS founders (like Sunsama's founder, Podia's founder, Trello's founders) on how they have thought about pricing their product, both high and low.