I just learned from another Nikonian that Nikon has doulbed the rebate on this lens to $100, which makes a used lens non-competitive, pricewise. Those looking to get one might as well buy new now, for about $420 shipped.
Brian, I am not sure about the warranty thing. I only filled out the registration form once when I bought my N80 two years ago. I never bothered sending in my F100 registration form or any lens. Am I making a big mistake? I mean,I have the receipt and warranty card, that's all they need. I see teh registration more of a marketing thing.