Sticker Shop

The Sticker Shop is a unique area in which reinforcements and special Plantable Plants/Consumable Zombies can be purchased in Plants vs. Zombies: Garden Warfare. Stickers can also unlock a variety of vanity items, though these items have no impact on Plant/Zombie performance, health, damage, or weapons. The Sticker Shop can be accessed in the main menu, or on breaks in between multiplayer rounds.

Consumable Items
These items are used up when you activate them, making them single use. These items can be Common, Uncommon, Rare, or Super Rare.

Customization Items
Customization items let you make changes to the appearance of your character or class. These changes are purely cosmetic, and do not alter gameplay.

Characters and Weapon Upgrades
The sticker pack's will give you different Characters and Weapon Upgrades I would say you should buy 40,000 pack's because you will get a RARE or SUPER RARE Character but if you want Weapon Upgrades you should get the 20,000 pack's because they will give you 9 items a high likelihood of a character piece, weapon upgrade and at least one super rare item.

Trivia

 * If you are in between rounds looking at the Sticker Shop and the timer has ten seconds left or less, the Sticker Shop will have a sign that says, "Sorry, the Sticker Shop is closed. A new match is about to start!" However, if you are looking at the contents of a sticker pack, then this won't happen.
 * The music for the sticker shop is the same as the music playing before you go to it.