Sex doesn’t sell these days—at least not without a price cut or two. The glorious 4,500-square-foot brick-and-limestone house at 615 3rd Street in Park Slope started out asking $3,800,000 back in February (when it got the HOTD treatment) but scaled back its expectations with a $400,000 trim yesterday. What’s it gonna take to get this deal done? If you had this kinda dough, what would you buy right now? GMAP