Widest rectilinear prime for a Canon under $1000 with excellent IQ?

Are there any ultra wide (18mm or under) rectilinear (non fish-eye) prime lenses for Canon mount that sell for under $1000 than will be sharper than my Canon 17-40L lens at the wide end? All there seems to be are lenses in the $400 range (which I'm assuming won't have excellent IQ) or well over $1000, which I can't afford. For use on my 5D Mark ii. Thanks!!