Sorry to hear your Squeezebox Transporter has died.
Had a Squeezebox3 and a Touch in the past.
Would you able to stretch to a Mano ULTRA mkIII.5 Farad Music Streamer (but no screen)
Or within budget a MATRIX MINI-I 4 PRO Music Streamer
There also a few 2nd RPi products in the ‘For Sale’ category
and
but you would need to add a screen and a case, so this gets and looks a bit DIY.
So the
Eversolo DMP-A6 GEN 2 Streamer (or even the
EVERSOLO DMP-A6 GEN 2 MASTER Streamer, if you can) is probably your ticket as a drop in replacement, for SQ, usability and looks.