if you're new to riding fixed, check your local craigslist first. you can probably buy a complete fixed or ss bike for $100 if you just want a beater. I did that, and honestly, I didn't like it. I may try fixed again at some point, but I realized quickly that I'm a roadie and I like gears. I'm glad I only spent $200 on my fixie, which I was able to recoup when I sold it. honestly, unless you're buying high-end lightweight stuff, I don't believe these bikes are worth more than that in any case, and I can't believe it when people tell me they spent $4 . . . 5 . . . 600-1000 on a bike with no gears, heavy wheels, steel frame, and only 1 brake. dumb.

get a used steel vintage frame that fits you. pay as little as possible. paint it black with spray paint. buy a fixie wheelset from nashbar and a single square taper crank from ebay. buy some new tubes and reasonably good tires. LEAVE AT LEAST THE FRONT BRAKE ON THE BIKE. rewrap the bars with tape that matches your rims. go ride and get compliments. quickly realize that if you actually like cycling fixies are a terrible fad like fat bikes and will be dead in 10 years. sell your fixie before that, make money, and invest in a proper bicycle.