The answer is yes and no.
You do have to pay dues to get certain benefits. Such as your service hours will count for Key Club, you can receive a stole upon graduation, earn Key Club awards, have the possibility to earn scholarships, receive a membership card & pin, and be allowed to attend Fall Rally & DCON.
If you don't pay dues your service hours can still count to the school's requirement, but will not count for Key Club. You are still able to participate in all activities except DCON, Fall Rally, and a couple of others. You are unable to be eligible for a stole upon graduation, unable to receive Key Club awards outside of 'member of the month', and you are unable to apply for scholarships.