i'd probably buy some chinese earphones if i'd needed any. right now i use the ones that came with my phone:
they are available around $20 separately, and might be a good pick for someone looking for a comfy fit and some non-fatiguing, warm tone.
i also bought a pair of fostex te02n's:
https://www.amazon.de/gp/product/B00GBMFZP6/ these are japanese, and also some hidden gems. they have the fastest bass response i've heard from any cheap earphones/headphones. i have some fit issues with them, none of the bundled tips fit my ears for too long, so i use the meizu's instead, but soundwise, these are hard to match at this price.
@Stevie: beats are overpriced, and when working out, you'll probably sweat a lot, so i wouldn't mind spending too much for earphones to use in gym. these should sound fine:
http://www.gearbest.com/sports-fitness-headphones/pp_469338.html
http://www.gearbest.com/sports-fitness-headphones/pp_356162.html