The cheapest bundle, at $49.99, includes beta access, 2500 credits, a two-day early access, a month of Patron status, two extra character slots, two extra inventory rows, a character potion bag, a Founder title, and a multipurpose Corgi pet.
The $99.99 bundle stacks on even more Patron status and credits, plus a Vanguard title and talismans. For $149.99, you snag all that, plus more credits, more Patron time, a Harbinger title, and a polar bear mount, among other perks.
From the FAQ:
What is Patron Status?
Patron Status grants all sorts of game boosts, benefits, and more. We will be sharing in-depth details about Patron Status as we approach launch.
What can I buy with Credits?
You’ll be able to purchase all sorts of goods from the in-game store including mounts, pets, boosts, costumes, and more. Credits spent during Alpha and Beta will be returned to you at the beginning of Head Start. Stay tuned for more details!
Check out the details of all three tiers on the official site. Trion has not announced dates for Devilian’s alpha and beta phases.