It’s a deal that gives new meaning to “moving house.” Nantucket is offering the bargain of a lifetime: a free $3 million-dollar home on the upscale Massachusetts island — as long as the owner is willing to move the house off the land within six months. The unusual pact is part of the island’s Demolition Delay Bylaw program, which gives away dwellings to incentivize homeowners to transplant them to new locations rather than demolishing them and adding to the waste stream. “Why would we put these