Probably going to take some hate here.
I kept buying Kershaw's, and at $60 a pop for the Kershaw Black Blur Glassbreaker Knife with SpeedSafe on Amazon, I was getting tired of it. They would literally walk off.
Like a 7/16 wrench in my shop, or a 10mm socket, shut the lights off and they run away to knife/tool/fairy land.
At KOH2014 a guy stopped by my pit tent, and I needed to cut a ziptie and he whipped out a "Derma-Safe" razor blade. Was awesome! I went to hand back and he said, no keep it. Turns out he was an ER Dr. and they have piles of them, and he grabs a handful a day it seems like, is what he said.
I got back to Texas, and a month or two later looked up the website on the side of the knife.
http://www.derma-safe.com/
I could buy 100 of these little razor blades for $60. So I did. 3 weeks ago I ordered another 100 as I was down to about 15 left (granted I have given away 30-40). so close to 2.5 years to go through roughly 60 myself.
I throw away when dull, or I break. They are so small you dont notice them in your pocket. Throw a few in the cupholders in all of our cars. have a grab tub at the shop and one at the house with a couple handfuls in each. They do 99% of the cutting I need to do. Now you cant gut a deer, or get in a fight with a mexican with them. But its all I carry now. weigh nothing, cost $0.60 vs. $60. My last Kershaw walked just before summer, and I decided to not replace it this time.
They are mega-mf'er sharp. Its a freaking razor blade. They arent for everyone. But for $60 for 100, and that 100 will last ya a few years easy, its hard to not try them out. Maybe goin halfsies with a buddy 50 each for $30 each.
http://www.derma-safe.com/