Ebay is a very useful place to start if you are looking at getting into cycling - you can save a lot of money by buliding your own bike through Ebay. You will find wheelsets, groupsets, frames and forks or any individual cycling part you need. Many Ebayers have built a complete, excellent quality bike for a fration of the price it would cost to buy a new one of similar quality. Whether it road, mountain, bmx or city bike - a whole range of parts can be easily found.
The beauty of building your own bike from the frame up, is that you get exactly what you want.