In good faith, we made a reservation in June 2007 for two short haul Canada-US flights in Aug using 15,000 Aeroplan miles. Due to unforeseen circumstances, our flights had to be canceled two days later (well outside the 22 day no-cancellation window) since we could not travel at that time.
The fee charged was $286.00 for recovering the Aeroplan points, or 102% of the original ticket price! When we called to inquire, the agent called this a "reasonable" handling fee.. I can imagine a 10 or even 20% charge, but not in excess of 100%.
BEWARE - The cancellation policy was NOT displayed during the web booking session; Aeroplan has refused to refund even a portion of the charges. It would have been cheaper to buy a cash ticket and throw it away.