Blizzard has detailed how World of Warcraft players can get their hands on the various different 20th-anniversary items, and what currencies they need to spend.
Several different currencies are needed to purchase every item in the celebration. There are the traditional Gold and Silver, Bronze Celebration Tokens (which are used for various 20th-anniversary items and Tier 2 Transmog items), Timewarped Relic Coffer Keys which get you loot from the Blackrock Depths, Masks of Honor (which get players access to legacy weapons and armor) and other smaller currencies.
There are also ten different anniversary vendors, all of which are selling various different pieces of equipment. Among them is the Time-Displaced Thanthaldis Snowgleam, who provides access to PvP-themed weapons and armor that scale with the player's level.
As stated in a developer insight on the official blog, discounts will be in place for these items, along with it becoming easier to earn currency after the first few weeks of the rewards being available. This will essentially allow the players who want all the possible items to get them, and if they don’t, then these sets will be available in future years.
Any players who collect one hundred tokens throughout the event gain the ability to earn additional tokens. This means, essentially, that it’ll make the Tier 2 sets a lot easier to buy. After purchasing the first set for sixty tokens, the second set will cost forty tokens, and after purchasing the second set, any additional sets become twenty tokens. This means those who really want these items can get them easily, and it won’t make multiple sleepless nights for the player.