Thank you! I'm a big dude (6'5" and about 350 lbs) and I found it on Amazon. I like it a lot.
It's reasonably pricey, but it's still on sale for about half off!
Boss Office Products Heavy Duty Double Plush CaressoftPlus Chair-400 Lbs, Black https://www.amazon.com/dp/B0050PSVZ6/ref=cm_sw_r_apan_glt_i_6K9TN4AHVA711WCT7JG5?_encoding=UTF8&psc=1
So the bad news is you wont find anything under $120 (I'm assuming USD) that's designed to support your weight. If you do find something comfortable it will probably wear out quickly. If you're willing to go a little more expensive though, you can get this chair for $192 on Amazon right now. This is the chair I used for several years before switching to a standing desk. It's designed to support someone up to 350lbs and the armrests are wider apart than most chairs so you won't be cramped. The frame is all metal and feels extremely sturdy. It was the only sub-500 dollar chair I've ever used that I could sit in all day without problems.
EDIT: I'm 6'4" and ~280lbs, so I say the above as someone about your size.
I've been looking at this: http://www.amazon.com/Boss-B991-CP-Double-Caressoftplus-350-Pound/dp/B0050PSVZ6/ref=sr_1_1?ie=UTF8&qid=1437672364&sr=8-1&keywords=B991+chair
I'd even consider the DX Racer even at its high price if I could get a cover for it.
My next chair is going to be something like this. Double plush, wide, and simple design. I like a lot of cushioning for gaming sessions.
I'm sitting in this one right now!
https://smile.amazon.com/gp/product/B0050PSVZ6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
I work from home, and I occasionally make my lumbar vertebrae very angry, so I wanted something sturdy and supportive, with a nice wide seat. This does the job well, and the upholstery seems like it'll last, too. (I wanted something that wasn't bonded leather, because it seems like that stuff peels and sheds EVERYWHERE.)
The chair is super comfy but also a little pricey. It's still on sale though. Lumbar support is okay but nothing exceptional
Boss Office Products Heavy Duty... https://www.amazon.com/dp/B0050PSVZ6?ref=ppx_pop_mob_ap_share
Found it on sale on Amazon. It's made for big ol' fat guys like me and is comfy as fuck.
It's pricey, but still almost half off on Amazon
Boss Office Products Heavy Duty... https://www.amazon.com/dp/B0050PSVZ6?ref=ppx_pop_mob_ap_share
Im 6'0 and 330. I've had this one for a year or so and am pretty happy with it.
https://www.amazon.com/dp/B0050PSVZ6/ref=cm_sw_r_cp_api_8FhcAbB2PMJRP