Google announced on Google+ that they added cost data to the AdWords Attribution Modeling.

Google already had conversion data shown for the various models, including first-click, linear, time decay, position-based, and last-click. But now, advertisers can see the cost side of these reports. Cost data adds the ability for advertisers to evaluate how CPA and ROAS change. “This allows advertisers to change their bids accordingly, reflecting the actual value of each campaign and keyword across the full conversion path,” Google said.

Here is a picture of the new report:

Here is the example given:

Forum discussion at Google+.