Which SSL certificate is right for me?

Standard SSL provides you with all the features you expect of SSL including
99% compatibility, a SSL site seal, 24×7 support and up to 256-bit SSL encryption.

Premium SSL provides you with all the features of standard SSL including unlimited sub domains.

This only requires you to buy one SSL certificate for your entire site and all sub domains, i.e. blog.company.com.au ill be covered. It also provides security for both non-WWW and WWW domains.