Where are your White Faced Spanish from? Yes, the breed is rare, but even Ideal hatchery sells White Faced Spanish. Fine quality Spanish would be worth quite a bit, hatchery birds wouldn't be worth much at all.
I would do more research on your birds. If you want to breed your birds, and you want to sell them, then you need to know what to cull for. I suggest investing in the Standard of Perfection, or looking for the Spanish standard online.
Post your birds here, and see what the White Faced Spanish breeders think of them. (And I'm sure there will be a great deal to learn on that thread too!)
https://www.backyardchickens.com/t/527029/white-faced-black-spanish-enthusiasts-come-hither/140