Bra sizes are confusing. More often than not, a woman is not wearing a correctly fitted bra, doesn't know her bra size, or doesn't know how a bra is fitted.
Cup size is dependent on the "number" part of the bra size... a D cup in a 34 bra is a different size from a 42 bra.
That being said, bra manufacturers are not held to any uniform standards when it comes to cup size and shape... that is why one brand of bra might fit you very well for a given size, but not another brand. Or, you wear a 34D in a Victoria's Secret bra, and a 34C in another brand, for example.
When discussing breast size after augmentation, outward projection can be further determined by the "profile" of the implant. High school geometry: Height (projection) times Width (base width). A Higher Profile implant will give you a larger cup size for less volume than a Moderate Profile implant.
Furthermore, a saline implant looks bigger than a silicone implant of the same volume. That is because a saline implant is more oval (round on both top and base), while a silicone implant is flat on the base.
Some plastic surgery books have proposed the following parameters for breast augmentation:
32 bra: 100-200 ml per cup size
34 bra: 150-250 ml per cup size
36 bra: 200-300 ml per cup size
38 bra: 250-350 ml per cup size
Prices will vary by region. $8000 is high for Florida. I cannot speak for Japan or New Jersey.