1) The 550 Family Plan isn't available in all areas. I noticed this when I still had a friend's northern Miss. ZIP code in and didn't see it, but I saw it when I had my Atlanta-area ZIP in there. Weird, yah. So I should mention it may be 550 minutes for $59.99, or you may be stuck paying another $10 for about 700 or so minutes.
2) If someone was asking about the $9.99, that's just how they account it on my bill. It's a $59.99 plan, but it shows up as $50 for the first line, $9.99 for the next one. I can add a third (which I have) for another $9.99. So I've got 3 voice lines for $80/month plus all those stupid taxes.
If this is highly confusing to anybody, well, it should be. I only know all this from investigating for about 4 years and having a relative that works for them. Why they can't make everything simpler is a mystery. I wonder how many CSRs even know what the heck they're selling.