+1 on RevDevil's comments
To give it some range though - I change out my 100/200 set that I travel with somewhere about after about 5 or 6 shows, so anywhere from about 200 to 350 knives - but I use them on 95%+ of the knives I do at shows. On those knives though they don't usually do super heavy work. Meaning I don't re-profile for folks at shows I just clean up, flatten and create an edge with them. When I change them out they are still cutting just really slowly. I do use 50/80s sometimes at shows but only on really bad stuff, or things with no edge created at all, or combat knives/survival knives/machetes and the like. Using the 50/80s for heavy work will preserve your 100s, but the trade off is you put in deeper scratches that are harder to polish out.
The rest of my diamonds, 400 to 1000 have never been changed out and they have done 3000+ knives probably.
Using them for just personal sharpening, you would use those coarse stones mainly just once per knife depending on its starting condition and how long you go between maintenance touch ups. if you stay on top of maintaining the edge after the first time you'll use mainly the finer diamonds or even just strops.
but the wicked edge looks pretty awesome from what i looked up about it!
