Greg bought a painting for $15 at Nancy’s garage sale.  Afte…

Greg bought a painting for $15 at Nancy’s garage sale.  After cleaning the painting up, Greg noticed that it appeared to be an original van Gogh and took it to an art appraiser.  The art appraiser told Greg that the painting was worth approximately $10,000,000. When Nancy learned that the painting she sold to Greg was very valuable, she called Greg and told him that she deserved at least half the value of the painting because the $15 payment did not constitute adequate consideration for a priceless painting. Greg disagrees with Nancy’s allegation and maintains that Nancy is not entitled to anything since he bought the painting from her at a garage sale.  Is $15 adequate consideration for a painting valued at millions of dollars? Explain your answer.