So now I finally have the money to upgrade lenses. I'm thinking of a telephoto ranged lens for the 40D. I shoot a lot in low light conditions so f/2.8 is a must. So far, I looked at the Tokina 50-135 f/2.8, Canon 100mm f/2.8 macro, and Tokina 100mm f/2.8 macro. I'm looking to spend at or under 500 bucks. Do you guys have any other suggestions?