stationary USB DAC vs portable all-in-1 DSD player - range of quality difference?

Debating between something like this, a Chinese portable DSD player, vs something like a FiiO K5 or K7. What sort of quality difference might be expected between the two? I'm also open to other suggestions, just looking for best bang for buck - while also getting the best quality possible, and considering the difference in features. 

Portability and not having to boot up the PC to listen to music would be nice, but if the quality difference is that large, then I wouldn't mind only being able to listen at home with the computer.

I have upwards of $250 to spend, and a pair of Beyerdynamic DT770 Pro 80 ohms. I'm disabled and rarely have extra money, so it's important that I can spend it the best way when I do. Music is one of the few things in life I can still enjoy from time to time.

If there is another DAC and/or portable DSD player you know of that is slightly more expensive and the quality is that much different, I may be able to swing it.

On a side note, I've been messing around with this $15 USB type C dongle I got off amazon that supposedly renders at 384khz (max) - any idea how much of an improvement on that I may see with the other devices I mentioned? (has anyone ever tried any of these cheap dongles to compare to more expensive dedicated DAC setups?)