Marthas Vineyard Buyer Agents. We are Exclusive Buyer Agents representing only buyers in the purchase of homes for sale in Edgartown, Chilmark, Vineyard Haven and across Marthas Vineyard Island. When you work with the Realtors from Marthas Vineyard Buyer Agents, you gain access to knowledge, integrity and our vast network to help you find the perfect vacation home, year-round property or summer home for sale on Marthas Vineyard--be it land, a residential, vacation, or investment property.