Thanks for all the answers,
I think maybe I'll review my money saving options and try that sharpening thing again! I was sure that the coatings were a bit thicker than .0001", but that doesn't really matter, what matters to me is that I can still sharpen them!
BTW, I have just found a stash of the old tips (all sorts) which I used about 25 years ago, at the back of my workshop.
