using pk points instead of money (default)

i'm using the demise pking source and client, which is a delta base, and it already has a pk store. it uses kills to buy items not money as currency. where would i look to change an items currency from money/default to pk points? i know how to make each item worth so many kills, but if i only put an item, for example rune platebody, as 5 kills, it still takes the default/money currency instead of pk points? any ideas :s? thanks.