“You wrote about adding e-mail accounts for $10/each; but the e-mail I got from Apple over the weekend says that additional e-mail accounts are $20.
Adding Email-Only Accounts
You can add up to ten 5MB email-only accounts to your full ..Mac membership, each for $20 a year. Keep the Mac.com name of an existing .Mac trial account or set up a brand-new account. Just log into .Mac, click Account in the navigation bar, and then Buy More. “