depends on how big the bucks are....
For Power:
chapest bag for the buck is probably a dry shot n2o kit
then a 1397 kit
the a basic turbo kit
For twisties:
assortment of front & rear sprockets
Forks & shocks
Brakes levers, calipers, rotors, lines, and pads
All around:
PMR top triple clamp (so the front height can be adjusted
Adjustable rear links (so the rear height can be adjusted)
Brighter headlight (for those after sunset rides)
Adjustable rear sets (to adjust to your height and ride comfort)
yellow box or speedhealer (to know what your mph realy are)
Just my thoughts though