I picked up my 50mm with a hood for $90 shipped. I really hope that your shooting Canon because I really want to check out a fisheye first hand.
The high end p&s (point and shoot) have auto focus points. I know the Canon g6 does. I think that model was discontinued though. Check out the Canon s3 is that one might do it for you.
you can see the vignetting when you look through the lens, if you're zoomed all the way out you'll have a full vingette, the more you zoom in the less vignette.