That's no cheap. Learning how to start a fire with what you find in nature is cheaper and a hell of a lot more practical for a real world situation. I do carry a CC sized magnifier in my wallet but, I can start a fire with flint and steel or a hand drill.
NRA Certified Pistol, Rifle, Shotgun and Metallic Cartridge Reloading Instructor
California DOJ Certified Fingerprint Roller
Ventura County approved CCW Instructor
Offering low cost private basic shooting and reloading classes for calgunners.