A classic shingled house on  Massachusetts ‘  Billionaire Isle  is up for grabs, and instead of costing millions, the house is being given away for free . The catch? You have to move it off the current owner’s property. No, this doesn’t have to do with  erosion . Nantucket — like many oceanside areas — has seen some home prices  plummet  due to erosion, forcing some homes to be moved or demolished. But this house — at  140 Surfside Road  on the southern side of the island near the airport — is located far enough away from the shore that erosion isn’t an issue. Instead, the house — a 1,736-square-foot, three-bedroom, two-bath Colonial on a little over an acre — is being given away as part of the island’s Demolition Delay Bylaw program. This is part of a longstanding island tradition of offering up  homes for free  rather than demolishing them and tossing them into the island’s one landfill. The tradition was codified into law in 1997.…