Madison Sporting Goods via eBay offers the Mongoose Men's 700c Detain Fixie Single-Speed Bike in Black/White, model no. R4044WMA, for $149.99 with free shipping. That's the lowest total price we could find by $50. It features an aluminum frame, single-speed drive-train, flat handlebars, high-profile rims, and front and rear alloy brakes.