If you can't afford $100 per tooth, you are not charging enough for your services and/or you have operators that don't care about the equipment. IMO, if you charge anything less than $150/hr for the smallest skid steer machines with a brush cutter, you will lose money in this business. Working in a union controlled state like Illinois, you better charge even more to stay in the black.
I've managed to stay in the black in this business for over 18 years. The best contracting advice that I ever read was, "Don't worry about winning every job you bid but be sure to make money on every bid that you win." Winning a losing bid ensures a loss and losses add up faster than wins.