You can buy a few at a time. They are not sold as a complete set, and are not listed as timed items. So, they will presumably be available as long as there is stock available.

However, as you probably realize, Tony is not prone to order a lot of product just because they are getting low. The minimum orders China is requiring is causing him to have to think carefully about re-orders.

ANd to further confuse things, don't forget the ornament versions for Key West and Sea Pines that will be available only from their own gift shops.