In your budget a combo streamer/DAC has some great choices. 5k will land you well.
Consider amongst many..
Lumin new or used
Brooklyn bridge
PS DirectStream DAC used
HiFi rose touted up above
Buy good Ethernet cables and hold off on learning about signal in optimization.
Aurender streamers/DAC are excellent but will not work with Roon You may find you go that route too. Many do. Qobuz has a free thirty day trail.. others too