Erik +1 Love Ayre; price? Used? Sure. Economical? Get one anyway.
Bluesound is good enough for any pair of headphones as well as Mytek gear.
I presume you have matching headphones i.e. the HD-820 'phones ?
I use HD-800's and Antelope Zodiac Platinum DAC + Clock,as well as the HDV-800 headphone amp to play my stuff directly to ears via Roon.