Looking for gaming *HEADPHONES* (not headset) under $50 (planning to attach a modmic to it)

Solution
I'd definitely suggest browsing forums like head-fi and other sites more focused on audio. You will be able to find much more comprehensive explanations there as they are probably more knowledgeable on the subjects.

Through some quick searches through forums, I find a very popular headphone for general purpose (music, gaming, movies) in the ~$50 price range are the JVC HARX700 and HARX900 headphones. Thousands of people chose this as the best bang for buck by far in this price range and they look like they have pretty good construction and materials for the price. I won't spell out all the pros and cons about it, but they seem like a great pair of headphones and I would definitely put out the extra 15 bucks and get the better one...
I'd definitely suggest browsing forums like head-fi and other sites more focused on audio. You will be able to find much more comprehensive explanations there as they are probably more knowledgeable on the subjects.

Through some quick searches through forums, I find a very popular headphone for general purpose (music, gaming, movies) in the ~$50 price range are the JVC HARX700 and HARX900 headphones. Thousands of people chose this as the best bang for buck by far in this price range and they look like they have pretty good construction and materials for the price. I won't spell out all the pros and cons about it, but they seem like a great pair of headphones and I would definitely put out the extra 15 bucks and get the better one.

Update: After doing some more research on the HARX900s I've found that it is a very easily modifiable headphone and after some simple mods people say that it rivals the sound of DT880s (a $300+ set of headphones). I don't know how true that is, but I'd say it's worth a shot.

Links:
HARX700- http://www.amazon.com/JVC-HARX700-Precision-Sound-Headphones/dp/B0013OWPV4
HARX900- http://www.amazon.com/JVC-HARX900-High-Grade-Full-Size-Headphone/dp/B0013P3ZOE

Reviews:
700- http://www.head-fi.org/products/jvc-harx900-high-grade-full-size-headphone
900- http://www.head-fi.org/products/jvc-full-size-headphones-model-ha-rx700-wired-headphones
 
Solution
Here's a great pair of headphones in your price range, just look at the reviews:

http://www.amazon.com/Superlux-HD668B-Dynamic-Semi-Open-Headphones/dp/B003JOETX8/ref=sr_1_1?s=electronics&ie=UTF8&qid=1444850654&sr=1-1&keywords=superlux+hd668b

And if the pads aren't comfortable (what do you except), here's some nice pads to go with:

http://www.amazon.com/Cosmos-Velvet-Replacement-Cushion-Headphones/dp/B00KLPRQMO/ref=pd_sim_23_1?ie=UTF8&refRID=1ADJGPY6P76DKESJNR28&dpID=41rk-Az70uL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_