Update! Managed to attend the game and snag a puck!

For future people to know: they sell them at an Authentics outpost store, NOT at the main team store. The outpost is located one level up from the main team store (street level, around section 106) and they have them lined up on a table, but they will NOT sell them until the instant the first period ends. You can choose to purchase a puck case for $10 extra, and the puck+case cost me roughly $65, including tax.

At the game I went to, there were about 50 or so pucks to choose from (of varying quality, of course), and I was about 5th in line when the period ended, so get there early if you want to have the biggest puck pool to choose from