Park N Fly Self Park is $40 per week always:
http://www.paylessairportparking.ca/
"Bus service provided by Park'N Fly", as well as parking lot and ticket machine.
I just tested the site - PArkNFly has hidden the coupon for March 1-30 - busy time for March Break traffic. When it goes live again you should print some of the coupons. I didn't get any to share.