I would definatley wait until you are18 because you be more developed and so will the rest of your body! I am 24 and I am getting mine done and I have seen 5 different doctors! The prices range any where from 4,500 - 10,000... It depends what doctor you choose and what you decide to get! I don't know where you live but I'm in Indianapolis Indiana and I am going to one of the top doctors in the United States and mine are going to cost 5,000. Breast augmentation usually ranges around what I am paying, but if you decide to get extra work then yes it will be more costly!
