Joe Wants to Propose to Rhonda and Goes to a Jewelry

Joe wants to propose to Rhonda and goes to a jewelry store to purchase an engagement ring.After college,Joe had worked as a jeweler while going to law school and is now an attorney.He still remains knowledgeable regarding the jewelry industry.In the jewelry store the owner listens to what Joe wants and he takes a diamond ring from a showcase.The jeweler tells Joe that it's a class AAA perfect blue-white stone in a platinum setting and the price is $5,000.Joe,without indicating his jewelry knowledge,asks to use the jeweler's loupe (eyepiece)and upon inspection sees that it's a Class AA yellow white diamond with three minor laws.He furthermore realizes that the ring is only worth $4,000.The ring is beautiful so he decides he'd like to buy it.He asks if the price is negotiable and the jeweler offers a sale at $4,500.They settle on $4,300.When Joe proposes,his girlfriend says no.Dejected,Joe seeks to return the diamond ring but the jeweler refuses so Joe sues the jeweler for fraudulent misrepresentation.Who wins and why?