Okay -  so this is where I really disagree with the vast majority of doctors who inject Botox, many of whom do an excellent job.  I don't do either - at my office we charge by volume based on the standard recommended vial dilution of 2.5 cc. 

I don't like either area or unit pricing because I think it often leads to a less than optimal Botox outcome.  Here's why.  When I see my Botox patients, even patients I've seen for long time, I customize their Botox very specifically for their face and draw detailed maps.  And, I often change that map from visit to visit after looking at exactly how their face is moving now.  It changes.  For example, a patient going through a divorce may be activating different facial muscle groups than they did before. 

When the pricing is by unit, patients and doctors start to focus on that rather than the ultimate outcome, which is to have a more relaxed, balanced and beautiful face.  The point is to do a stellar job.  If a patient comes to me and says "I only want 10 units today,"  I may have to compromise so much that I can't do a good job for them. 

When the pricing is by area, then it leads to a different series of problems.  Suppose the "eye" area costs $200.00, but the day you come in, the muscles aren't very active.  I may only need a few drops there to keep the area quiet for months.  If the standard amount gets done, it leads to that over Botoxed look and wasted money.  I often will put a little more in one area, a little less in another, treat a new area, and completely skip another one -  all keeping the total volume and price the same.  That way I can do a very customized treatment.

Also, see my article on the average costs of procedures to know what is reasonable. 

Hope this makes sense.  Dr. I