Diapers.
Love 'em or Loath 'em, parents are always ready to start potty training before their babes.
For this comparison, I specifically used Pampers Baby Dry in size 2. All sizes are the same price, just different amounts. In my own experience, I found we used size 2s the longest, and started potty training in size 4, so it is in the middle - although there are size 5s available.
These prices are all regular price, no sales, coupons or discounts.
Amazon for the win! And delivered to your door!
Loblaws, Real Canadian Superstore, and Well .ca all get honourable mentions.
I am shocked at Rexall's price - but Shoppers was eye opening as well!