Ryan McAvoy said:
But when I discovered you had to pay a fee to take the game to 100% completion, I was absolutely disgusted. Like turning the page to the last chapter of a book and finding a white page with the words "F*ck you pay me" typed in middle.
I just looked into this. There are just a couple areas that can't be fast traveled to that can be hard to find. DLC doesn't count at all toward the percentage toward completion.