You can deploy an app on Heroku with a DB for about $20 per month.

I would try to launch something as quickly as possible, because that’s the quickest way to learn. Come up with an idea, work out how quickly you can get something out (ideally less than one month), charge for it, then scale up your servers when you have people paying you.

Yep - about $500 MRR at the moment and 6,465 total users. Launched on Hacker News and have been getting organic traffic since

https://www.prettypolly.app

It lets you learn a language quickly by speaking with AI. Launched in August and got 2 million server hits in the first week! Would recommend others launch on Hacker News if looking for a boost.