I called my TA to ask her to check into the Carnival 1 day only sale with free upgrade. I also asked her to look into upgrading to a balcony. She called back ELATED - had called Carnival and got a quote for an upgrade. An unbelievable $150 TOTAL for 3 people. She just couldn't believe it! When she called Carnival back to upgrade me, she found the agent had misunderstood - thought she was asking for 2 people.
Turns out an upgrade for 3 would be $350.