I think Adwords is still cheaper than Adbrite. The reasons for this is because some of the sites figures are totally wrong when they come to predicting how much traffic they have been giving to other sites, you normally get less clicks than what it says in your stats and the traffic is also very untargetted by the looks of things.
in general yes, cheaper, much cheaper, but since i target uk traffic only for me is not cheaper... it is more than 2 times cheaper than adwords for uk traffic