Is Juvederm Only Sold by Two Vials?

$550 is about average for a single syringe of Juvederm, not two syringes, so it appears you paid about what is normal for a single syringe of Juvederm.
Juvederm does come in packets of 2 but of course these can legitimately be used for two different patients.
It is best to air the problem directly with the doctor rather than have it bother you, even if he is Division Chief. However it appears as if the billing was about normal for a single syringe.
If you did get two syringes for $550, you got an incredible bargain, with a price so low it is probably a mistake... in your favor!

Juvederm Ultra is a hyaluronic acid filler that is commercially available in units of 0.8 cc. Your experience may not have reflected the surgeon's motives or policy, but rather the policy of the administrative office. Since Juvederm is bought in units of two syringes, it is understandable that a mistake could have occured. Just ask the surgeon and it should be remedied. You should only pay for what you need.

Juvederm is sold in packages of two, but, it is common to sell the patient a single syringe for use. I take extra time to go over the exact amount of filler I am recommending prior to injection of the filler. The changes can be subtle from injection of filler and patients feel like you do not have their best interest in mind if their bill exceeds their expectations. The answer you received from the front desk staff at the time of your visit was likely misinformation from the front desk, not the physician's policy.