Banks based in Florida and out-of-state competitors that do business here have all paid heavily for the high levels of loan defaults in the state. Stuart-based Seacoast Banking Corp. of Florida wrote off more than a third of the roughly $100 million they had made in real estate loans, most for construction and land development. Chief Executive Officer Dennis Hudson III said that should represent the peak of bad construction loans, and said the bank was readying a massive liquidation sale. Wachovia Corp., the largest bank operating in Florida, took $8.86 billion amid $6.1 billion in write-downs in the second quarter. Ken Thomas, an economist and Miami banking analyst said housing prices probably won’t stabilize until the middle of 2010; he doesn’t believe more optimistic projections from groups such as the National Association of Realtors.