You're in good company!
We bought a place where we're going to live for some time and made the investment in finishing our detached garage to be the permanent fish and plant room. It's insulated, heated / air-conditioned (split unit), has skylights, a deep sink with on-demand hot water, a semi-automatic water changing system (i.e. I turn on the water and it adds water to each tank)... with overflows to a main drain), a central air system, etc.). It's probably $100 per month in electricity.
I have about 60 tanks out there and can spend as little or as much time as I have available. I've had more manual fishrooms in the past and - although I got it down to maybe 2 hrs or so per week to change water on all the tanks - it was still work...and time which I didn't and don't always have.
A common trap is trying to turn the hobby into a business. I'm much happier keeping only the fish that I enjoy and not having every tank filled than trying to keep and breed fish that are profitable but not really what interests me.