Option Options backend for my app

Good day People ,

I’m from Casilda, Santa Fe, Argentina
I am new to Ionic,
I’m starting to make an app and I’m investigating all hehe technologies and need someone with experience to guide me a little favor.

My application needs to store information to work off line, have enough background information and then the user must always have the information generated in the cell that working in the farm without internet connection and my doubt storage system use.

The options assessed are:

  • Firebase: i read that allows offline storage, works fine with Ionic? I worry how they grow prices when one scale, Someone used in any app with many users?

  • SQL Lite + PHP + MySQL backend: This is the option that gives freedom, but I get a little scary having to program all the functions for which the database is kept current in the cloud

  • Sql lite + backand: someone tried?

Some extra recommendation?

Thank you very much !