Buying piecemeal can also be cheap if you have the time, patience and knowledge. I'm doing this for a frame now and am picking up parts off of ebay on the cheap. The bike will have Ultegra shifters, 105 derailleurs and a Campy crank. The basics of what you need to know are that you need to keep speeds consistent, such as 10 speed stuff only works with 10 speed stuff. You'll also find that rear wheels are compatible with either Shimano/SRAM or Campagnolo because of the cassette on the rear. The other thing is that rear derailleurs must be paired up with their respective shifters (although Microshift shifters work with SRAM and Shimano). I also have some parts that I am looking to get rid of so PM me once you figure out if you're going Shimano, SRAM or Campy and need some things.