Because who wants to look like everyone else?
Of course, supporting your local brick-and-mortar vintage shop is the best way to find unique shit.
Stores like Procell in Manhattan and Magpie in Portland, Oregon maintain a customer base and reputation based on a highly defined knack for finding what their customers are looking for. If you live in a reasonably sized city, you probably have a rad vintage store you should check out.
Learn to love Uniqlo.
Uniqlo has long been the secret of fashion bros everywhere. Do you think they're really spending racks on designer everything? No. They're getting perfectly slim khakis, button-ups and down jackets from the Old Navy of Japan.