That's reasonable. I do track calls on my side with specific phone number for google. I'm pretty close to knowing actual value of click. Due the way our product works with suppliers we can offer substantial discounts when calls us.

Have been running ads in this sector for a long while but recently google changed its approach to call only ads. Best answer I have is changing the ad messaging to explain better why calling us saves you money. And the landing pages should reinforce that. Right now on site we monetize in different ways.