When research has an obvious and immediate negative outcome that's a cost. The difficulty/expense of the research is also a cost.
The "benefit" would be the incentive to know the outcome. This may be profit, military advantage, academic kudos etc.
Maybe the problem with the type of research being discussed here is that there isn't neccesarily any agreement that the outcome is negative. For many people, I suspect this will remove a lot of the weight on the "cost" side of things.
I'm not making a specific point here - I'm actually trying to work this out in my head as I write.