Dollar per kg conversion for those numbers, this is /Canada on .ca after all:

• The Turkey the dad bought last year: $8.82/kg
• The Butterball in the picture may be as cheap as $7.45/kg, or as expensive as $9.11/kg
• Walmart $6.61/kg
• across Ontario at Independent $5.51/kg
• other Loblaw stores are $4.40/kg

Were all the prices you saw the same brand?
I don't eat animals, so I don't really have a solid price in my head for what it should cost. I do remember as a child that Butterballs were more expensive, so we never had one.