I would pay too for an easy editor. Considering that there will probably be a Baldur's Gate Act, and looking at the dimension of the current map, it's easy to say that BG map alone can allow people to conver a huge number of existing D&D adventures and campaigns with limited need for extra maps.
If someone is smart in WOC, they should see the opportunity and start releasing campaign packs as DLS for BG3, even unrelated to the main story. I would buy each one of them, I fear...
