How to start charging beta users?

Hi IH!

The task management chrome extension I'm working on has been downloaded (with a 1:1 zoom onboarding) ~130 times and we have ~30 power users (people who use it 5+ days a week).

We want to know whether we are adding enough value in order to charge but don't want to come up as rude. Most of the power users are friends and family and the initial reaction of 3-4 of them to us charging $10/month was negative (too expensive/wouldn't pay). How should we approach this? Should we attempt to charge all 30 power users or should we make the product better so that it's clear it's worth money...or something else :S ?

Thanks a lot for any advice