Before anyone asks, yes, I do have a smartphone, but it's a Chinese one that, while performs okay, doesn't have the best sound. I'm currently using my old phone, an old blackberry, but it doesn't have much storage. It does have an SD card slot, but this was a temporary solution in the first place, so I figured I may as well begin looking for a proper MP3 player.
Info about what I'm using it for and preferences:
Decent sound, I'm not particularly picky, but I don't want something that sounds like crap. I want something that will get me the most out of my $200 IEMs
I'll only be using this for music, other functionality would be nice, but I don't need it
Something under $150, willing to go higher if it's worth it
Battery life should be decent, not necessary, but I'd prefer it if I didn't have to charge it everyday
Again, another preference, but something that will let me change songs/volume without having to take it out of my pocket