And when my butt itches, it usually means its going to cost me a shit ton of money. In this scenerio, I'm itching for a Nikkor 24-70mm f/2.8... But at $1700, I wouldn't be alive to use it. I have an opportunity to get a 28-70mm f/2.8 from my wife's uncle who never uses it for a little over half the price, but I'm curious how it compares to the Nikon 24-70 I want and the Sigma 24-70 I have now. I'm sure its better than the Sigma wide open, but is it worth $900? I'd sell the Sigma to get it if it came down to it.