Can a $750 system sound good?

Of course!  If you only spend money where it matters. 
Streamer - very marginal gains, if any at all, over a Raspberry Pi 4 plus Allo HAT.  $100. 
DAC - Khadas Tone Board. Excellent. $100. 
Any class D low distortion amp. $300. 
Van Damme cables at $4 per meter. 
Mark Audio Alpair 11MS full range drivers. $150. 
$100 left for some birch ply. 
Then get the free plans for the Frugalhorns Mk3 : https://www.frugal-horn.com

Bingo! 

Another option is to spend $700 on the best active speakers you can find, $50 on an Audioquest JitterBug, and hook them up to your laptop.