Baker sells; Adam buys 0 1 2 3 4 5 6 Cakes per day 0.60 0.80 0.95 Cost / Worth (in Y) Baker’s Marginal Cost Adam’s Marginal Worth Price = 0.90Y Baker self-sufficient (Q = 2) gain region MC = 0.80Y MW = 0.95Y 3 0.80 0.95 3rd cake: Baker's cost 0.80Y, Adam's worth 0.95Y; price 0.90Y. Both gain — Baker earns 0.10Y over cost, Adampays 0.05Y under worth.