Question about Fiverr Promotion!

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Do you think setting "Auto" CPC is better than setting "Fixed" CPC?

I am setting Auto CPC. But last months that charged me $667.

Previously I used Auto also. But never charged me more than $200-$300.

But last month that is charged $667.

I know it says my income is $3112 but there more than half from my repeated clients who knocked me from Promotion 1-2 months ago. When they give another order, it is marked as Promotion again.

 

Now I wanted to set $0.5 CPC for my all 10 gigs.

Please suggest me what I should to do to minimize that kind of higher promotion cost.

Thank you!