A jewelry store and a jewelry retailer had a contract for the sale of a necklace by the store to the retailer for $40. The fair market value of the necklace at the time of the contract was $130. The store breached the contract and did not deliver the necklace. At the time the retailer learned of the breach the fair market value was $120, and the retailer believed it could resell the necklace to one of its buyers for $170. Which of the following represents the most likely recoverable measure of the retailer's damages, not counting incidental and consequential damages