[maxtheaxe]

Looking again at the Stewmac version, it appears that they've actually reduced the price compared to the first time I saw it, by quite a bit...I remembered it being well north of two hundred bucks.

Their version is still more than twice the price of this one I found on Reverb...maybe created by a guy with machining skills/tooling who copied the design, with brass knurled adjustment nuts instead of the steel ones, perhaps other shortcuts/variations that aren't obvious (or simply a lack of overhead).

I agree that it still would not be worth it simply to have a "single-use" tool, especially if you have a good luthier nearby who would do it cheaper than the tool. However many of us, who may not be paid luthiers or even know a good one nearby, might have multiple guitars that need new parts on occasion, or buy guitars to flip them, from people who weren't willing or able to do what was needed to set them right.

It takes me a long time to properly grind a nut or saddle, because being obsessively careful with these things I have to stop frequently to check my work as I go; if nothing else, this will be a huge time-saver and I will know for certain that the base of the part will be precisely flat.