Hosting the server is free. I’m actually not sure about windows because I don’t use that. We actually play on our iPads. We have a family set up. Pay once for the app, everybody gets to install it on their own device.

For free stuff I think people run Java edition? Again, I’ve never done that. There is an itzg Java server container https://github.com/itzg/docker-minecraft-server

FWIW Bedrock lets you connect to servers online that have free games to play like Bed Wars, Sky Wars, Block Party. I don’t know if Java has that.

My kids and I use https://github.com/itzg/docker-minecraft-bedrock-server and I would recommend it.