Since I started building I have been using cheap acetylene torch cleaners for bass, and a set of feeler gauges that I cut teeth into with a rotary tool. These approaches worked OK, but were VERY slow, and while adequate, not at all better than adequate.
So my wife decided that maybe I should get a real set of nut files for father's day. So I decided to go for it! ...but it turns out I am still a cheapscate. Also how do a get a set that will work for electric guitars, steel string acoustics, classicals and basses without breaking the bank?
Best deal I have found: Shopping the sales I found a set of 10 Hosco edge cut files on Amazon for under US$ 80. I think this will do pretty much all of my guitars, as well as the G string on a bass. I looked at the cheapest way of adding the three that I still need for a four string bass...and ended up on a website called "Plaza Japan." There I found the cheapest price I have seen for individual Hiroshima Uo-Chikyu nut files in the sizes I needed for 6,945 Yen (US$ 43.).
This still seems like a lot for tools I don't use much, at least until you price them at StewMac. Also factor in that I think the Hiroshima file company makes these files for Hosco and Stew Mac. Maybe the price is not so astounding when you consider that it seems that one company in Japan makes most of the acceptable quality nut files in the world.