I assume you can only be grandfathered if you already had an account when the increased the charges a year or so ago.
I haven't seen any selling of grandfathered accounts, and I guess that it wouldn't be all that easy. Accounting information to change etc.
Also, whereas some people had several $6.95 enom accounts and could sell off spare ones, most people probably only ever had (or needed) one NW account, and they are probably reluctant to give it up due to the potential $10 saving per name.