If your question is aimed at getting a good estimate for an honest price in the classifieds section, I couldn't possibly say.
If you like to know how much you need to get one: not that much. I've seen them go for < €15 at eBay.
If you inquire for insurance purposes: recently this one (eBay #220353662274) went for US $136.50.

Bottom line: it varies a lot. I bought mine at a price somewhere in between, but a lot nearer the low end of the scale. I think this goes for most of us.

As always, a lot depends on how it is offered; with a good description in the right place and a mention on our forum, or eg. in a another language in an odd category with spelling errors in the title. Note that the linked one was classed under 'Strops, Sharpeners' as well as under 'Antique Boxes'. Some Mauchline ware collectors might even pay more for them than hone lovers.

I suppose those looking for a hone would pricewise want a mint hone in a tattered box classified as Mauchline ware, and Mauchlin ware collectors would have best luck finding a broken hone in an excellent box offered in the sharpeners section.