The base game is free
The Epic Games Store FAQ explicitly states that in-app purchases are not required for the core gameplay experience. Console listings also describe a free base game. You can play without buying a preorder edition.
What are the paid editions?
Advanced and Collector’s preorder packs were optional paid additions. They enabled early console preloading; that historical benefit is not an entry requirement for the now-live free game. Check current regional prices before purchasing.
Read each edition’s contents before buying. The PS5 Advanced Companion Handbook description includes a Prismana egg and evolution materials, so paid content includes more than cosmetics.
Currency, extra content and subscriptions
The official FAQ confirms paid currency and add-on content. The current US PlayStation listing includes Lumin Crystal currency bundles alongside the free base game. Check your regional store or in-game shop for current prices and any randomized-purchase probabilities.
The official FAQ says PlayStation Plus and Xbox Game Pass are not required to purchase or claim preorder packs. Cloud-streaming access has separate account requirements.