If you want to coast, you need a single speed rather than a fixed gear. As others have said, a complete build from just the frame can be really expensive. One possible solution would be to find an inexpensive, used "donor" bike that would have many or most of the components you need and then transfer them to your frame. If you want tips on building a single speed or fixed gear without breaking the bank, check out this website: http://sheldonbrown.com/fixed-conversion.html. And this one: http://sheldonbrown.com/deakins/how-...onversion.html.