Domain for $18?

I just bought a domain 2 months ago. If I attempt to purchase a second domain through that account, I’m given the $18 option. If I start from scratch, I am only given the option to upgrade to WordPress Premium for $99 per year. Was my previous account grandfathered in or something? The WordPress website still advertises the $18 option but for the life of me I cannot find it on this new account!