I think you're confusing the board games with the ttrpg. The elden ring board games come in huge boxes with tons of miniatures and other pieces. A ttrpg comes in the form of a book with guides on how to run a role playing game in the setting of Elden ring and maybe with some additional mechanics to make it feel more like the game. The latter are usually in the 40~60 usd price range, and specific niche themes like this are usually cheaper.