Well, I'm tired of having my D50 sitting on my table because all the lenses I want are way too expensive. So until I my birthday comes up in August I want a lens so I can just starting using my camera and get used to it. Someone I know is selling a Sigma 28-80mm f/3.5-5.6 for $65 shipped to my door. Is this lens at all decent? Is the $65 worth it? thanks