Ask IH: Your app mvp under $1k

Hey everyone, please help me validate my idea:

Essentially I want to launch a set of fully developed MVPs including its backend (PHP) + native iOS Objective C + Figma file) of specific/generic mobile apps.

I will only sell 50 licenses per MVP (so as not to flood the market and protect the first few buyers)

The first MVP I'm thinking of building is "Calm/Headspace for X".
Basically to sell any premium audio content on a standalone iOS app.

What are the things you would take under consideration?
Would you buy it?
What type of app would you like me to build next?

Thanks!