Now that is a good question.
I have a pair of Sony CH900 bluetooth headphones.
I have this version as opposed to the CH700 as they handle hires audio (What they really mean is that is can also connect to an output by cable WIRED)
I have a headphone amp (DAC Dacmagic XS)) by Cambridge Audio that plugs in to the USB port of my laptop. It can also by used with the USB port of my phone.
Also I have the Cyrus Soundkey. With is a USB headphone amp (DAC) mainly for portable use (low powered)
I did consider buying a hires portable player, but then after buying these DACs, I considered that it was not worth it. The DACS cost me £39 and £79 respectively. It's £200 for a decent hires player.
.. and come to think of it. My phone (Samsung S22) handles hires files just fine. In fact my old Samsung S8 handled hires files just as well.
Both used with my Sony CH900 and my AKG K550
Now I am not saying that these headphone amps are as good as a hires player, but I do not have any complaints with them.
Are these hires players overpriced?