due to a rapid decline in the price of horseshoes, which can now be bought and sold for 50 cents each, mark refuses to buy 1,000 horseshoes from

due to a rapid decline in the price of horseshoes, which can now be bought and sold for 50 cents each, mark refuses to buy 1,000 horseshoes from clark for $1 per shoe and thus breaches an existing contract. clark is entitled to recover