Navid R. said:
i recently bought the book for D&D 5E 'princess of the apocalypse' IRL. i really want to use it in ROLL20 without buying it separately in ROLL20. if someone knows how i can use the IRL module without building it separately in ROLL20, it would help a lot. thanks!
I know it was just a typo, but that sounds like a great adventure title. :)
As others have noted, you are paying for not only the content of the book but having it in a format for Roll20. As an adventure creator on the marketplace, I find it can take half an hour per page to get it in a place where it can be sold on Roll20 with all the maps, dynamic lighting, hyperlinked handouts, NPC character sheets, linked tokens, etc.