Well you can't do much better than getting a Cheney frame......they have been making racing frames for a very long time.

However.....your $2,000 frame is only the beginning as you will need a $950 shock, $500 triple trees.......and some form of fancy fork.  Then you have to figure out what you are going to do for wheels, brakes, fuel tank, seat, controls, electric system........before long your build thread will look very similar to the Beer Budget Board Tracker thread!

Go for it!

Framecrafters want $4500 and 8 months, they must be busy!  
How does anyone fix the VIN problem if they want an upgraded frame?

I think that process varies by state and it's not available in all states. Check on the process before investing time and money.