Subscription in the app. How much to ask for money?

Hello! I am a developer and created my app. The app is free without ads. There are premium features. How to calculate the cost of a subscription so that everyone is happy?

I set $0.99/month. However, there are people who like the application, but complain that the subscription is expensive.

p.s. If you are interested in what the conversation is about: https://play.google.com/store/apps/details?id=link.dothis