Is a Fat Transfer Worth It For A BA to Go from A-B Cup?

Fat transfer to the breasts is still a developing procedure, and generally not a good idea for most patients. The results are unreliable and the amount of improvement is questionable.

While your size goals appear most compatible with what fat injection breast augmentation can achieve (1/2 cup or so), the issue is one of reliability of the result. Fat injection breast augmentation is far from a perfected procedure and should still be viewed as a work in progress. How well the fat takes and what size can be achieved, and the cost and effort to do so, remain issues that would not be considered completely reliable. A 'traditional' breast implant is the most assured and cost effective approach to achieve your breast size increase goals.

It is my opinion that fat grafting should not be done to the breasts for purely cosmetic results, a small implant will give you a guaranteed result and you will not get excess calcifications in your breasts when you have mamography as you age.