Linode is super cheap. I pay 6 or 7 bucks a month for a bottom tier VM.
Feel free to message me and I’d be happy to help with server stuff.
I'd be happy to help if you need anything! Whether hosting or just backend related questions!
Also depending on how hard coded your architecture is, maybe you can separate out the Magic specific data from the app itself? So the MTG specific data could just be loaded as a datapack?