Quite a few people are already working on WBE. Not very many people are working on friendly AI. Taking this into consideration, I think an extra dollar is better spent on FAI research than WBE research.

This is true for the general categories "FAI research" and "WBE research", but very few of those WBE research dollars are going to studies of safety and policy, such as SIAI does, or (I assume) to projects that take safety and policy at all seriously.