I stopped at a $1000 hone, thereabouts. Each time I use it I estimate I use something like 0.001% of the hone (maybe 0.0011% if I use slurry). So that's about 1000 * 0.0001 = 1 cent.

I shave off a 1 cent edge.

In all seriousness though, it really isn't as simple as "highest grit". It also has to do with pressure, and what happens on the hones of lower grit leading up to that final grit, and the razor itself. Sure, when things settle down and you become a consistent honer, then the final finisher may make a difference. But until that time there's probably more variation in your day to day honing than there is between your hones.

As has been said before, you can have the highest grit hone available unto man, but unless you have it right at the beginning (bevel), all you have is a really nicely polished bevel on each side. If those sides don't meet at a fine enough point, even a $20,000 super duper Jnat won't help you. This is known as the "polished turd effect" in the scientific literature.

James.