A hair clipper that I bought 10 years ago. Cost me 25 euros. But a hair cut costs 20 euros. I need one every month (because I'm partially bald). So 20 * 12 * 10

A hair clipper that I bought 10 years ago. Cost me 25 euros. But a hair cut costs 20 euros. I need one every month (because I'm partially bald). So 20 * 12 * 10 = 2400 euro savings. That's a 9600% return on investment! I should have bought more hair clippers...