Comment by asah

...in the real world, A tells B that he "sourced" the deal and therefore deserves a bigger cut and in the real world, B agrees up to a point (the $30 mark). Over time and rounds of playing the game, the A's of the world learn where the line is and optimize to stay on the correct side of it, only testing the other side 1-2% of the time to see if rules/behavior has changed.