Same old question, just thought there might be some new answers.
Is it worth buying the AUS CDI for the gain in advance??
What will the HP increase be?
What is the price of the AUS CDI? (2009)
What is the part number for the 2009 CDI?
Where can i get one in the USA?

Yeah i know,,,,, I'm too lazy to search tonight...

 

IIRC correctly the plugs aren't even the same so they aren't even plug and play, but maybe i'm not remembering right.

Raycour has some tests run on his programmable CDI for the 07 models and does not see any power difference with stock bore, but that might chage with the big bore kits.

Personally i would go with cams and pumper carb before i went chasing down HP with the ignition system (assuming big bore already done with full exhaust).

 

Already have the pumper and exhaust covered. Cams will be next, and i think Bill Blue has a head swap with bigger valves but i am not sure if it is worth the price for the gain.
Have to check into it more.

 

Here is the aftermarket one.

KLX250S Programmable CDI module | eBay