The Cosmetics Shop offers item bundles for each class that can be bought with Palladium currency.
Diablo 4, like past Diablo games, will require players to purchase the base game. It's not free-to-play, like PoE.
Players can purchase cosmetic items through an in-game store. These items won't affect power at all.
Despite the growing trend of NFTs, Blizzard will not include them or other cryptocurrency tech in Diablo 4.
Premium Currency is obtained via the Season Pass feature and can be used to buy seasonal cosmetic bundles.
Buy cosmetics, not power
Blizzard is well aware that Diablo fans don't want Diablo 4 to have pay-to-win mechanics. It's made a vow to have aesthetic-only microtransactions (MTX), as it's done with Overwatch and World of Warcraft. In addition to microtransactions, Blizzard will make money off Diablo 4 with sales of the base game and expansions. Although NFT use is surging in gaming, Blizzard won't use them (yet).