Recommendations for Cost-Effective Online Database Solutions?

I'm looking for some online database solutions and could really use your suggestions! I've come across a few options like MongoDB Atlas, Neon, and Supabase, but their monthly prices range from $0 to $30. Since this is just a pet project, I would prefer something with a usage-based pricing model because sometimes I need to go over the limits of those free plans. I need to perform searches similar to `where textfield like '%keyword%'`, which makes Firestore seem unsuitable for my needs. Both SQL and NoSQL options are welcome, so if you have any recommendations that fit these criteria, I would love to hear them! By the way, I've decided to host a Postgres database based on the suggestions I receive.