When you improve an attribute with karma do you pay for the augmented rating or the unaugmented rating if you have augmentation. The book says "The cost for improving a natural attribute rating is the new rating x3." So if you have a strength of 5 and a muscle augmention:1 for 5 (6). If you raise it, do you pay 18 (6x3) or 21 (7x3)? I know in SR3 bioware improved your natural attribute. Would I be right to assume that concept went out the window with SR4?

if it says natural rating, then it means natural rating, i would presume.

unless of course you're talking about the adept power, at which point you're screwed.