I tested my facebook campaign following Zeno's recommendation on pricing:
These are the results:

And I created 3 ads per Ad Set. Exact same copies.

As you can see, the cost is about the same for the clicks. However, what I don't understand is how the manual bidding of $2 per click not taking into any effect.
Why is bidamount=automatic so much better than bidamount=2 even though my bid amount is significantly higher than bid amount?
Obvious question but it's worth asking: are all other parameters besides the bids absolutely identical?
Even a small difference in targeting or even creative could change bids significantly.