You need to check into this ASAP. It's not legal to hire employees without it. And you really don't want to risk it for how little they charge. It's around 4% of wages, a little less, for us with our mowing and general landscape guys. I had a guy cut off a finger, and another guy cut a tendon in his hand. Both of those could have put me out of business and potentially put me in serious financial debt. Even if your guys have health insurance, there health insurance is going to come after you and they will win. If you are going to skimp on stuff, buy inexpensive used trucks! Don't skimp on general liability and workers comp. They are all cheap insurance to be sure! By the way, minor injuries or stitches I pay for myself, as a business cost, but I used workers comp for those two huge items.