Depending on if you are willing to drive a little, or want to visit friends, I see a flight on Wednesday, December 19 at from Calgary return for $395 all taxes in... leave YEG at 21:30 on AC8165 and return by 23:49 on AC8168... only 30 minutes between flights in YYC though :-)

Or better yet, just go one way for the minimum 500 status miles (you are Elite) and then rent a car and drive back or something like that if you want to keep the costs down?? Just would increase your time :-)