Discounting trains the wrong customer
The default medspa growth plan is a Groupon, a $9 per unit special, and a Black Friday package. It fills the calendar with people who came for the price and will leave for a better one, and it caps what you can charge everyone who would have paid full rate.
The economics of this business sit in the second visit, the third, and the tenth. An injectable patient who stays is worth several times the first appointment. Marketing built to win the cheapest first appointment works against the only number that matters.