As far as I know, at least in Canada, they are the same price, + or - couple of hundred.I'd probably do the same if I could afford it Congrats and enjoy. From what I've read it is an incredible beast of a car.
08 Smoky Granite Mica IS-F
If you can afford the F you can afford the AMG.
Just my 2 cents.
Ohhh and no way would I ever buy a Mercedes, I have a few friends that have them, I have been told you should not even look at a Mercedes the wrong way because they might just decide to brake down on you for looking at them the wrong way.
My F has 42000 km so far, I am at the track almost weekly, besides that I cant keep up on tires, rotors and pads, not a single thing is ever been wrong with it, and lets not forget it was made in Japan.