Way to go to town on everything I wrote Axilrod. Perhaps one reply/quote, rather than 3, would have been sufficient?
My point is that the OP doesn't know what lens he wants. For well under his budget of $2000, he can test out all the focal lengths he is considering, (35mm, 50mm, and 135mm) and see which focal lengths he enjoys working with. Then if he wants, he can upgrade.
If he knew he wanted a 50mm, or a 35mm, or a 135mm, and he is willing to fork out the cash, then sure, dive right in with an L lens. But I don't see the point in diving in headfirst without trying out the focal lengths first.
Alternatively, he could rent all three of the 50mm 1.2L, 35mm 1.4L and 135mm 2.0L for a few days and see which he prefers before laying down the cash.