Thank you for your question and photos. You will need every bit of "extra" fat to get your desired results, based on what I'm seeing in your photos. So, yes, I would liposuction the entire back and bra rolls area, as well as any other area from which I could obtain fat.
I would recommend an in person consultation to evaluate how much fat is available for the transfer. Fat can be harvested from multiple areas like arms and thighs. Seek a plastic surgeon who performs hundreds of these procedures, has great reviews and photos, and is an expert in this field.
Thank you for your question. The cost varies depending of the Doctor and the location. I would suggest to contact a board certified plastic surgeon.
Kind regards