"I care about so can't see the point of adding the extra cost for the G9"
How much extra are you looking at?
The G9 is a higher market camera, and although not as new, does have a much faster processor than the newer lower end camera.
The image quality may be identical if you capture the same image, does the G9 not have features that will help you capture the image, that you may wish you had further down the line?
It may be cheaper in the long run to go straight to the G9, than get to it through G90