depends on what you mean by kit?
You can buy just a new set of pedals for $30ish bucks (depending on fiberglass or CF) or you can buy a pedal and cage set, something like a VForce3 or G3. These are more like $130ish
the pedals are a nice upgrade, better response, while the pedals and cage is a definite improvement. Well worth the $$ IMHO.