Hey guys. I have never bought another lens before, and I'm still using the one that came with my XTi. I'm looking for a new lens because I get the feeling that I don't get the best quality with this lens, especially since they are sold for $70 on ebay, which makes me suspicious of how good they are. Anyways, in a new lens I'm looking for something that has great range, from something around 18mm to a decent zoom, that's in the $300-$350 range. I've come across this lens: http://www.amazon.com/Sigma-18-200mm-3-5-6-3-Digital-Cameras/dp/B0007U0GYS I don't know how good the f/3.5-6.3 is, and I know that it doesn't have Image Stabilization, but what do you guys think of this lens. Is there anything comparable on the market? Should I get this lens? Thanks.