The best way is to chang ethe cost of the minerals to however much points you want to receive. Then change the condition amount to the lowest amount u have. If u change the amount something costs, you can change the score you get for killing it, at least i think. That way you can set several different things
Conditions:
CUrrent play has at least 25 kill score
Actions:
Subtract 25 kill score
add 100 ore
preserve trigger.