Danny Dodd was an avid coin collector. Further, because of his extreme wealth, acquired in a settlement with an insurance company a few years earlier, Danny was able to acquire all but the most expensive of rare coins without giving a second thought to the price. As most coin collectors, Danny also sold coins from his collection when he could find a buyer willing to pay a price for a coin that would provide Danny with a profit.

In September of 1985 Danny met Sue Staple who was also an avid coin collector. Sue expressed an interest in acquiring an 1867 liberty silver dollar which she said she would pay $2000 for if Danny could find such a coin for her. Danny did not have such a coin in his collection but was aware of another dealer who had one for sale for $1800. Danny and Sue entered into a contract for the purchase and sale of the coin in question with delivery and payment to take place on September 30, 1985.

Danny immediately contacted Mark Moran, the dealer who had the coin for sale and contracted with Mark to buy the coin for $1800 with delivery and payment to occur on September 25, 1985. On the day for delivery Mark called Danny and told him that he had sold the coin to someone else for $1900 and would therefore be unable to deliver the coin as promised.

Unable to find another 1867 liberty dollar Danny purchased a 1868 liberty dollar for $1900. This coin was, of course, different from the one he has promised to sell to Sue, but it was the best alternative that Danny could find.

On September 30 Danny brought the 1868 coin to Sue who refused to accept it or to pay the price, insisting that although the two coins had the same value that she needed the 1868 piece to finish her collection of liberty dollars and that she already had an 1868 dollar like the one Danny had acquired. Six months later Sue acquired an 1867 liberty dollar $2500.

Both Mark and Danny have breached their contracts. Discuss the rights of Danny against Mark and of Sue against Danny.