An SSL Wildcard certificate allows you to gain both time and money ! All the domains and the subdomains will be protected by an SSL Wildcard.
What is a subdomain ?

The use of subdomains allows to create from your domaine complementary and derived names. Contrary to basic SSL, the set up of a Wildcard SSL certificate allows to make easier the installation of the HTTPS to all of your subdomains.
The Wildcard SSL certificates available on Cheap SSL certificate garantee a maximum security level (encryption up to 256 bits)