Pre-launch
One pack before the doors open. It bundles enough to start comfortably, and costs less now than it will after launch.
Three phases, three prices. The contents never change — only the price does.
Buying early costs less: that is the only difference, and it is what you get for backing the server before knowing what it is worth.
A server costs hosting, backups and a domain name, every month. The founder pack covers that start. It grants no combat advantage, and everything in it stays obtainable another way once the game is open.