For last couple of days I am digging into Amazon advertising api and looking for a solution to find advertising cost using ASIN and Amazon Advertising API. The closest I could find is this Campaign Report.
It returns a list of campaigns with campaign id and cost per campaign. But Ideally, I would like to pass parameters like ASIN and a date or a date range, to retrieve the advertising cost.
Alright, I found a way to deal with this problem. There are different reports available with the api and sponsoredProducts solved my problem. It returns asin, impression, clicks and cost etc for a particular date.
I also used a github library, which made it very easy to work with the Advertising api. I'd surely recommend using this one -
https://github.com/amzn/amazon-advertising-api-php-sdk#requestreport