Diablo 4 is being operated as a live service. This means that the game will require ongoing monetisation to fund updates during its life cycle.
No Pay to Win
Blizzard has made it clear that items purchasable in the Diablo 4 short will provide no power advantage to player. Items available in the shop are purely cosmetic.
Blizzard explained in their August 2022 developer update:[1].
The way we approached designing the Shop and the cosmetics within it was by thinking about the experience we want players to have. We want buying things to feel good–before, during, and after purchase. So, if players choose to buy something, it should be because they want to, not because they feel like they have to. It should also be clear to players exactly what they are getting before they choose to buy, with no unpleasant surprises.
The Shop’s cosmetics build on top of the foundation of a huge variety of transmogs from weapons and armors players will find in-game. It’s also important to us that the Shop is grounded within Diablo’s world, so our cosmetics are holistic fantasies, the individual components of which can be mixed and matched with transmogs from armors acquired in-game for endless customization options.
The Shop sells cosmetics for Premium Currency. Cosmetics give players even more options to customize the visual appearance of their characters. Nothing offered in the Shop grants a direct or indirect gameplay advantage. So, while many of these may look like powerful pieces of gear, they have no in-game stats.