Hoovers appears to change it sometimes.
Right now, the main page had red text that says "Our minimum shipping quantity for chicks is 15. There is a minimum of 5 per sex and breed. We reserve the right to change order minimums as needed."
And if I look at the page for any specific breed, I find "Important: Our minimum chick quantity is 5 per breed and sex."
Prices are listed per chick, but they change depending on how many chicks you order. Ordering 5-14 chicks gets you one price per chick, 15-something gives you a different price, and so on.
Are you ordering directly from Hoovers? Or ordering through TSC?
If you order from Hoovers directly, you might order 9 or 10 pullets, and 5 cockerels, then plan on butchering the extra males after you pick your favorite.
Since you intend to keep a rooster, I am guessing you want to hatch chicks in future. Keeping the best one and eating the others can be good practice for when you do that.
You might end up with a male, and you might not. It's inconsistent, and seems to depend partly on the breed and partly on random chance.