I've previously purchased the Legendary edition and wanted to buy the Sourcebook Bundle to get the collection of books that have come out since then. The Sourcebook has a price of 305.88 but when I add the sourcebooks manually it's 154.90. I don't think it's taking into account for previously purchased content.

Somewhat similar situation for the Legendary Bundle but instead of wrong price, you can't add it to your cart at all.

Is the answer we need to add them all manually? In the marketplace screen, you can't directly add books. you have to click on each one, add to cart, go back to market place, next book details page, add to cart, etc.

You are not supposed to be able to buy the sourcebook bundle after buying the legendary bundle. Not only might it not count your previous purchase correctly, but it also won't account for the discount the legendary bundle grants.

Moreover, it is unnecessary. The legendary bundle gives you a discount on all future content equal to the discount of the bundle.