There are certain, lets say red flags out there.
Areas vs syringes. If the office will not tell you how many units you are getting. This is done to keep you ignorant about the actual dose. However, knowing the alleged dose allows you to compare office when needed. These products are measured in units. BOTOX and Xeomin units are pretty comparable. On the other hand Dysport requires about 3 times the number of units for a clinically equivalent treatment.
The advertised price per unit is less than the actual cost of the agent. A vial of BOTOX cost the doctor about $500 give or take in the United States. The vial contains 100 units. So if you are being offered a unit for $5, something is up because no one gives this stuff away for their cost. It is much more likely that the unit you are getting contains something less than a unit of agent.
In the United States, the is no independent practice of estheticians or register nurses, or medical assistants. Physician assistants and nurse practitioners are different. I personally believe that these treatments are best administered by the physician. So check with your State. If the situation is not legal, they may be cutting other corners including how much product you are getting.