Do you use Propellerads SmartCPC? How do you calculate the bid?

I am planning to start a campagin with SmartCPC on Propellerads, but I have no idea how to calculate the bid. I'm wondering if I can just start with the highest suggested bid, so that I can get more traffic and test faster, but I think it will require more budget and how to control the spending is a problem. Or I can start with a lower bid and increase step by step, but the traffic will be slowly and it need more time to test. Do you have experience with SmartCPC? What do you think?