https://stackpoint.io/#/pricing
They haven't announced a date for when they'll start charging, and I'm not sure how that will affect existing clusters.
What's wrong with paying for something as a hobby?
Many people don't have $50/mo to spend on unprofitable hobby projects. There's nothing wrong with paying for hobbies, but most people's hobbies fall under (a) infrequent large purchases or (b) really cheap occasional costs.
Upgrading my computer falls under (a). It's expensive but I only do it once every 3-4 years. Buying new guitar strings for my guitar every so often falls under (b). It's cheap and while I should do it every-other-month I do it maybe twice a year.
If the cost of new guitar strings was equivalent to the cost of upgrading my computer - I'd give up playing guitar as the hobby would become too expensive.