Well traffic is worth different values based on targeting, for one of my sites I have an eCPM in the $20 range, for my sales page I am expecting a $50 eCPM.
Leave it up to your judgement, if you feel that you can earn more then go for it and then haggle to get the price ranges to where you feel that it should be. People are usually willing to give up more if you challenge them on it individually
