I must confess that I was curious to know where this is heading and I really want to know the meaning of 'potato dollar' (lol)..

Not only did you explain 'potato dollar' to us, you actually went ahead to cook it and served it well. The explanation couldn't be more simple tahn the way it was presented. I have always wondered how the final payout credited to my wallet is being arrived at. Now I know better.

Thank you for the enlightenment @adsactly