I tried looking for the exact same info a couple weeks back. Practically every dialer company I taked to, was quite willing to give me a spreadsheet with the amounts they paid. I was only able to find 2 companies (both European) that listed the amount charged to the user.
http://www.goodthinxx.com/
http://www.ebs-ag.de/
IBill is also launching a dialer through a partnership with a dutch company called KPN Switchpoint. When I got the info from iBill a couple weeks back they had a list of payouts and customer-rates of a dozen or so countries.
Most dialer companies I've talked to seem not to want anyone to know how much the customer is being charged.