Discover the Diamond-Water Paradox—why diamonds cost more than water. Learn about subjective value and marginal utility in economic valuation.

Sean Ross is a strategic adviser at 1031x.com, Investopedia contributor, and the founder and manager of Free Lances Ltd. Robert Kelly is managing director of XTS Energy LLC, and has more than three ...

Marginal utility helps set product pricing; high initial satisfaction decreases with more units. Some stores use bulk pricing when consumers value additional items less. Progressive taxes assume each ...