I was looking into getting a new lens. I like to do some action shots but also like landscape. I was thinking of a telephoto lens. I have a Canon Rebel Xt with a polarizer and a nd filter. Which lens do you think is right for me? I was also thinking about selling the kit lens which is a 18-55mm. How much do you think I could get for this? I really like the fisheye effect but I'm not sure its appropriate for all my photos and may be nice as second glass.