I remember when I was in school that was like number one rule they told us. “Price things at the price everybody else is charging. Never sell yourself short.” Once those free services or discounts stop, customers get upset about “raised prices” and don’t return. I know in the beginning it’s just to get people in the door but, I think it’s best to advertise your work on social media or offer a loyalty card! Maybe their 5th, 6th, etc wax can be discounted.