How to pick a good headphone?

[Shammikit]

so i have a small budget of $20 and i want to buy a good quality headphone for music and gaming.mostly ill be using it for gaming.there are some headphones in my budget on ebay but most of them are Chinese and im not sure about their quality and durability.however according to their descriptions they seem to be having tons of features.are these headphones any good?

i also checked some headphones in the local stores. they had these headphones for my budget but they lack some features that the ones on ebay tells that they have:

skull candy icon 3
TDK ST-100 BLUE ULTRALIGHT STEREO HEADPHONES
SONY MDR-XB250/BQIN OVER EAR HEADPHONES
SENNHEISER HD 180 OVER-EAR HEADPHONE
Armaggeddon Fuze 7 Gaming Headset

 

[_Cosmin_]

You want to know at what to look?

These determine the sound quality (but you always should go and try them in person as every ear is diferent):
Frequency: 15Hz -20Hz(powerfull bass) up to 22kHz-28kHz
THX: that`s for distortion (should be smaller for better quality)

These are extras (optional things):
Dimensions, shape, weight - for comfort using prolongued periods
Folding - for easy transport
Mic for gaming / noice cancelation (some have external, other internal - matter of prefference)
Cable lenght (with jacks for changing when needed) / wireless (bluetooth LE) - with longest battery life.