1. Lip Filler Is Priced Per Syringe, and the Leftover Is a Policy Question
The thing you are charged for is a syringe of product, a fixed volume most often of one milliliter, and a practice sets a rate for that syringe rather than a price for the treatment. Everything else in a quote is built on top of that rate.
Lips are a small area, and a plan for them frequently calls for less than a whole syringe, which raises a billing question that never arises in structural work. What happens to the product you did not receive? Some practices sell a defined smaller amount at a set rate. Some charge the full syringe rate regardless, since an opened syringe cannot safely be used for anyone else. Some hold the remainder for a follow up inside a stated window.
Neither structure is dishonest, and the gap between them moves your real cost more than a small difference in the headline rate does. It is also the easiest thing to settle on the phone before you book.
Treat a bare number with no product name and no quantity behind it as a rate rather than a quote. Something you can evaluate names the brand, states how much the plan calls for, gives a total, and says what happens if the plan changes in the chair.