I now have the Nikon 24-120VR and Nikon 28-200mm f/3.5-5.6G lenses, and am considering getting rid of the 28-200 for a little more telephoto. Maybe 100-300 or something like that. I won't get a lot of use out of it, but would like the extra reach when I take an Alaska cruise in August. I did a search and found that "daodang" uses a Sigma 100-300 lens and seems happy with it. It's an inexpensive lens. I can get one for even less.... but will it do the "job"? From the shots I saw from daodang it seems it would. I know I'm a "price snob": If it's cheap it's no good, if it's expensive, maybe it's good. Comments, suggestions?