I bought a complete bike (2010 Madison for $330 shipped) and took it completely apart, sold off the parts I didn't want, which covered about 66% of the purchase price, and will be be building up exactly what I want, with nice components for under $500. I guess it's another way to go.
Without a doubt, you get more for your money buying complete, especially when it's substantially discounted, which is hard to find buying only components. But make sure you sell the sell the stuff you don't want to recoup some of your investment.