See pics, I can sell as a unit, or separate the audio boards from the Raspberry PIs. The HiFiBerry Digi boards are high end audio connectors. I used the rPI and Digi board with picoreplayer software and Lyrion music streamer. Basically turning my audio receivers into music streaming boxes for a whole house music system.
The Raspberry board is the bottom PCB in the pictures.
The Digi board is the middle PCB in the pictures and has coaxial and optical connectors.
Raspberry Pi 3B+ w/open case and power supply #1 = $40
Raspberry Pi 3B+ w/open case (no power supply) #2 = $40
Raspberry Pi 3B w/open case (no power supply) = $30
Digi+ Audio Board #1 = $35
Digi+ Audio Board #2 = $35
Digi Plus Audio Board = $30
The last board is an earlier model for the Digi+
https://www.androidcentral.com/raspberry-pi-3-model-b-vs-3-b - shows diff between 3B and 3B+
https://www.hifiberry.com/shop/boards/digiplus-standar/ - note, the boards I am selling are older versions but work the same.
https://lyrion.org/
https://www.picoreplayer.org/