Just for the sake of sharing prices in the context of North America— in Mexico 12 eggs go for $2.21 [1], 18 for $2.46 [2] and 30 for $4.90 [3]. This is just a normal supermarket, and the brand is just a common local one, not the cheapest and not the most expensive.
$3.50 for 12 off-brand is available in grocers
Google says today $6.79 CAD is $4.78 USD or ~0.20/egg USD