questionshow long will 4800 brushes last before re-ordering. Math, if it costs $6.18 to manufacture and they sell for $25, thats a profit of $18.82 That equals 3 times costs or 300% profit. 4800x$18.82=$90,336. ramp up the manufacturing to 25kx$18.82=$470,500x12months=$5,646.000 per year,just in the U.S. I think I can live with that. Boys and Girls, we have a winner here no doubt. Staying long on this one. Correct me if wrong, tia