A couple of things...
They won't charge the card until playoff game(s) are confirmed. This means the earliest they could charge cards would be December 30th, and the highest amount would be for the Divisional game.
No matter, and it holds for all teams, the most home games you can have is two. Do the math, you'll see why. Long story short, even though the invoice details show three games, you won't ever pay for three games.
The NFL actually sets playoff prices... there's a thing they do where they get all the ticket prices from all 32 teams, and do some math, and figure out the $$ for the whole building, and apply a ratio, and tell the teams to charge enough $$ to generate that amount of money. The precise details of which levels pay which dollars are left partially up to the teams, but 90% of the $$ is set in stone by the NFL. This is largely to keep inexpensive market teams from charging too little for playoff tickets, or big market teams from gouging for playoff tickets... you'll pay the same (relatively) for an NFC Championship game regardless if it's in Seattle (a relatively inexpensive ticket team0 or in Washington DC (expensive tickets).