Ouch. I'm not sure I'd buy all pieces at list either, but then if you want all new components this wasn't an idea you hatched in the middle of last night. You can always find deals if you spend the time to look around. Sapim, United Bike and Sheldon Brown all have spoke length calculators, some on-line (don't filch the numbers from the shop unless they're willing; they pay to receive the latest specs of rims and hubs for their calculating system). Lately fully spoked wheels are not a part of the business that shops keep up on anymore, making spokes harder to find in your lengths.