Moode Multiroom and BT: a better way?

Hi,

I want to be able to cast music/sound from my phone to several speakers throughout the house and move everywhere freely.

I saw that the latest Moode (9.0.4) allows for several "routers" to distribute BT to multiroom "clients" but as I understand it it would require (logically) require to stay within BT range of the first "router" we cast to.
Would it be possible to send sound from a phone (over IP) to a server that would use that input as a local web-radio? Could a Pi also do the same (with, say, sound from a record player)?

As I understood it WiiM would do the job, it's just that the price is steep.