What is the minimum amount of fat that should be transferred to each breast for best results (fat transfer procedure)?

In general, 200 cc per breast is typically the upper limit of fat injection recommended by most plastic surgeons.  It is not that more cannot be injected; but on average, this has been determined to be the most that can be expected to live during one transfer.  Multiple transfers would be required for additional cc's.  In general, the abdomen and thighs are preferred donor sites but fat from other areas can be used.
Some of the retention rate will depend upon the amount of fat transferred, as smaller volumes will likely have a higher survival.  Occasionally, a patient can resorb a great deal of the fat despite optimal transfer procedures. I typically transfer from 250 cc to 400 cc or so per breast.  Thinner patients are outstanding candidates in my opinion, because the fat transferred is extremely resistant.  
Results are largely dependent upon the skill of the surgeon, his/her ability to remove fat without creating contour deformities, and your expectations. You would need a consultation to determine the available fat stores.

You need a formal evaluation by a licensed plastic surgeon and expert in breast augmentations to determine what is best for you and your goals.Proper breast enlargement is not a "cookie-cutter" procedure where the same technique is applied to every patient. Every woman who comes to my practice has unique needs and different goals for her breast augmentation. As a board-certified plastic surgeon, I always listen carefully to each woman's concerns and thoroughly discuss the key points of the procedure. For those women who prefer a "Natural Breast Augmentation" without implants, fat grafting is a safe, natural, and minimally invasive approach that offers low-maintenance, long-term improvement in size and contour. After harvesting the fat from your body, we purify and enrich the fat before injecting it in the desired areas to improve volume and shape.
My experience performing thousands of aesthetic breast surgeries in a wide anatomical range of patients enables me to achieve consistently beautiful and natural results that are customized to each patient’s body type and goals. These results are the product of extensive communication, meticulous planning, and skillfully executed surgery.
I suggest consulting with a board-certified plastic surgeon and expert in Breast Augmentation surgeries. - Dr. Cohen

I would only consider breast fat transfer for filling in hollowing such as the upper pole area rather than using it for volume in general.  I feel that the disappointment is great when patients look at fat transfer as an alternative for breast implants.  No matter which surgeon is performing the fat transfer, some of the fat will dissolve and some would.  A matter of how much will stay is partially dependent on the technique, and part of it is not predictable.I would recommend you see a board certified plastic surgeon to discuss your options.  Specially if you are very thin and your surgeon could not harvest much fat, as it appears so, 125 cc per side is minimal volume.Hope that helps.