I've read the wiki. I've searched the forums. I haven't been able to make any progress towards making a decision about what hone to get.

Purpose: touch up only
Options (I think): Barbers, Coticule, Nakayama

I want a good stone that will give me superlative results. I'll leave the bevel setting to the pros. I just want to touch up.

Why are Nakayamas worth the $$$?
Why are Barbers hones so cheap?
Why do the honemeisters not use Barbers stones?

Please help.