Larry, not sure which is more $ up front or on going, but probably the dual, especially for the average driver. Still, the same cost/benefit can be applied to many things that perform better. Performance tires, high compression, high revs, complex valve train, etc. All part of the package when you buy a high performance car. I see the clutch as just another one of those. The dual was originally used because it "performs" better in the sense intended. For some people there is little if any cost involved because they use the car as designed. Others who use it for drag racing or just don't really know how to operate the clutch properly are better off with the later single.
So I agree with you, each of us must weigh these things for ourselves.