Originally Posted by MARIO K
Hey Dave, I'm currently using a t3i. Before I see my self spending large(r) amounts on a lens, I'd like to upgrade the body.
Don't buy lenses that you'll want to replace when you improve your body. Lenses will outlast bodies by several times.
I didn't know your camera, so you're not going to get true fisheye with a crop sensor. That doesn't rule out an 8-15mm, but it if you never plan to have a FF sensor, then it'll probably be a waste of money.