Ha, I like your thinking. Not to dampen your inspiration, but consider:

the price of a frame, which is going to be chosen first before parts. If you have a frame with non-standard sizing (seatpost, headset) you'll avoid having to send parts back.
Also consider the price of tools.
Then, a good wheelset. Don't forget tires/tubes, and rim tape. Add another chunk of change for cogs and lockring, if they aren't already installed.

Add all these up, and it makes sense to go with a complete bike, where you can just ride the hell out of it, learn how to work on it, figure out how you want to customize it, and go from there.

Also, learn how to use the search function. (I find google better than the forum search feature). Cuz if you're building your own, you'll be using it more often than you think