Charging for themes and tech support seems fine to me. As long as it’s possible to do it yourself.

They need to make money, to continue the development and that seems a good compromise

Don’t give them more ideas

Since it would make small quantities (at least at the start) and with better materials, I bet it would be also more expensive so maybe it evens out.

I would also buy it, I’m tired of household items that randomly break and the manufacturer doesn’t care.