I have always wanted to build a bike from the ground up. I am also wanting a full suspension MTB for next summer and a flat bar road bike for commuting the bikepaths. These guys have New Old Stock Avanti bike frames from 2010 - 2012 going for crazy prices. I just bought an Avanti Torrent Full Suspension frame for about $70. Frames don't come with forks or rear shocks but I plan to put my OzB skills to the test buying cheap components over the coming months to build up the bike(s).
This is not for everyone, these are just bike frames, not full bikes but they have crazy priced deals to clear them out. Deals like carbon road frames for $200 and Alu 29er hardtails for $60. Size availability seems limited, I got the last Torrent in a Medium.
If there are any cyclists out there thinking about building up a bike, this looks like an awesome deal. Combine it with the Groupset offers from Ribble and you can probably make a sweet bike for cheap!
That's a lot of pain and stuffing about though!
If you've never had any experience with modern bikes, you can have your hands full just trying to adjust the gears and brakes, let alone installing them properly from scratch.
For the person very familiar with actually working on bikes (and not just riding them and making little adjustments on the fly to avoid bike shop repair fees), this looks like a good way to save money.
For everyone else, I strongly recommend getting a bike put together by a pro. Full warranty if something goes wrong with a component is nothing to be sneezed at when you are paying hundreds of dollars for some of those parts.