[LastDayz]

I heard that there's no point because expensive headphones would just expose all the flaws in your MP3s because it's not the best or clearest file format.
 
Should I stick to cheap headphones like these?
 
http://store.sony.com/p/Stereo-Headphones/en/p/MDRZX100/BLK

 

[viralcow]

Get higher bitrate MP3's and you should be fine.
Not many people can differentiate between 320kbps and lossless, even with detailed headphones.

 

[LFC_SL]

Properly encoded MP3 files, i.e. ripped and converted from original CD are fine for the many in the context of outdoor commuting usage
 
And at a sufficiently high bit rate 256kbps or 320 kbps

 

[manbear]

You could do better than those $20 Sony's while limiting yourself to MP3s, but yeah, it would be a waste to get something that costs $600. This is obviously a huge generalization, but I'd say the $200-300 range is probably as high as it would be worth going. I'm assuming that you're not using an amp, just the regular headphone jack on a portable player, so how easily the headphones can be driven is also a factor. Headphones like the Sennheiser Momentum, Amperior, HD25, V-moda, etc. would all be worth the money with MP3s, IMO, especially if you get higher bitrate MP3s.