Does anyone have experience with CPA offer rewards app? How much "coins" should i give users per APP install or CPA offer completion?

I really am torn on how i should price each CPA offer completed on my Rewards app. Like I am guessing per each CPA offer i put on my rewards app I do like a certain % divided and that is the coin amount i should give them? I dont know and I am probably way over thnking this but i was wondering if anyone had experience with this if they could share any information on how they did it omfg i would so appreace it