The raptor springs are $60 each for the skis... or you can get the front and rear for $280 for all four.
http://www.raptorshocks.com/store/categories/Triple-Rate-Springs/
RAPTOR Shocks Website:
Our baseline triple rate spring kit for the Pro Rmk will help soften up the first half of the stroke while increasing the stiffness for the last half of the stroke. These springs are a direct replacement for your Walker Evans shocks and come with tuning instructions along with a cool spanner wrench to adjust them. This is the same spring package we use with our shocks with excellent results!
http://www.raptorshocks.com/store/categories/Triple-Rate-Springs/