you'd have to know your lines to know the answer to that. sometimes those curly coats molt out and become the nicest ones around, and other times they stick around and are useless to your herd...IF it sticks past molting though you can sell them as Astrex. Highly popular among the fanciers.
in my herd, when i had mini rex, the curly coats all ended up being worthless (to a show herd potential) when they molted into their adult coats, so I sold them as pets. But I've heard of the odd one that molts out and has a marvellous coat on it.