how does business work?

What I want to know is how much money is everyone making when I buy something at lets say Best Buy. Like lets say a radio costs $25 to manufacture

product Radio = $25 materials cost and labor
Manufacturer ?? % profit

Brand Label Company ?? % profit

Distribution ?? % profit

BEST BUY ?? % profit
What are the typical margins? Any business school people out there? How much will the radio cost me? and the middle men??