What would be the the cost for 3 syringes of botox for marionette lines?

It seems like you may be getting Botox and injectable dermal fillers confused. That is very common! Botox is a purified protein which reduces the activity of the muscles that cause wrinkles to form. It is most commonly used in the forehead, between the eyebrows and on the crow's feet. For the marionette lines and the cheeks, you will want to look into injectable fillers such Juvederm or the Restylane family of products. Those products can lift, smooth and plump an area that has lost it's volume. Injectable fillers range anywhere from $500-$1000 and can last up to 1 year, depending on which product you choose. Good luck!

Botox is typically priced per unit.  I think what you are talking about it dermal fillers, where they are priced per syringe.  Prices vary anywhere from $500-$800+ per syringe.