Where I live its $5 for a dozen local fresh eggs and there is a place down the road with fresh Organic eggs(all organic feed for thje chickens) at $7 a dozen, and these are the type of eggs that you make omlettes with.
$12 doesnt seem soo much for ones with little silkies stuffed inside of em.
I don't think the price is bad at all, even for a pet quality silkie eggs. Silkie chicks at hatcheries/feedstores range anywhere from $2.50-$4.00 each.
I sell my pet quality silkie chicks as day olds for $2.50 each. If you can hatch all 12 eggs, that's only $1.00 per chick. If you even manage to hatch out 6, that $2.00 a piece (cheaper than I sell pet quality for)
You could always sell extras that you don't want to help cover the costs of the eggs. Just my 2 cents.