I wouldn't buy Topman, it's trying way too hard to be "hip" or "hipster" and that's wack. Plus the quality is pretty sub-par for the price from what I've heard.
As far as Need Supply Co. under $50 section, that's a pretty good option but you won't find any really great items there. If you want to buy the kind of companies that Need Supply carries, start saving pennies because you are going to need way more than $50.
Your best bet?
Thrift Stores/secondhand. Hands down.
$50 can get you tons of shit at a decent goodwill.
Look for Woolrich and Pendleton Flannels, dope vintage tees, my friends have really good luck in the jacket section with leather jackets and peacoats so that's worth checking as well. Of course, thrift stores also have great sweaters. Look for sweaters made in US, England, or Scotland. You'd be suprised how many quality clothes people donate. I have found tons of Ralph Lauren, Lacoste, all that fancy shit for pocket change.
Shoes section is worth a look. I have seen some dope boots there, but never in my size.