[Casterina]

I'm looking for a pair of earphones within $50 which to replace my EarPods and Samsung earphones, I'll be using the earphone with my Galaxy S4 using PowerAMP to play my 320kbps music

 

[Thr0waway]

I'm an amateur on this topic but I think I may be able to help, having gone through this process myself.
First you should determine the sound signature that would fit you best. This website should help a little in determining what sound signature you may enjoy and suggests good IEMs in certain price ranges: http://theheadphonelist.com/articles/earphone-buyers-guide/.
If you have no idea what sound signature you may enjoy, link youtube videos of your favorite songs.