There’s no denying it now. There it is, in black and white: The Hamptons real-estate market is dismal. According to Prudential Douglas Elliman’s market survey released today, transactions were off by 53.5 percent in the first three months of this year, compared to last year. Only 145 homes found buyers. Things are better in the North Fork, where the median sales price fell 13.6 percent, to $443,500. Fifty-six properties sold there in the first three months, a 36.4 percent plunge. As for the luxury market, let’s just say it’s not too luxurious. There are 470 properties available in the top 10 percent, price-wise, of the market, about a third more than last year, and they’re getting cheaper: Median prices are down 24.7 percent.