To utilize your existing setup without breaking the bank, buy a WiiM Pro or a Bo6 if money is tight.
Download Plexamp on your phone or tablet.
Download the Plex server to your computer.
Add your music libraries to the Plex server.
Sync everything up and enjoy.
Your total cost about $150 for the WiiM Pro $50 or so for the other unit.
The Plex software is free although there is an upgrade path with more features.
Is it as super duper as the $2500 units? Probably not.
Will it get you started and familiar with the process at a minimal cost? Oh yes.