Plumber that hasn’t had a raise in 5 years

Been a plumber my whole like I currently make a base of 28.50 plus 10% commission on weekdays and 20% on weekends on everything I sell over a 1000$ I have asked my boss for a raise a few times but has said we have increased our pricing so you will see that when you sell more should I just quit I should be making 40 plus an hour as I am only one who can do the very complicated at my job should I quit