Chalet d'Amour

This home is priced at least a cool $1 million below the floor for comparable Greenwich houses -- and below what the empty land alone would cost. So the 3,826-square-foot, architect-designed contemporary? Effectively free.

Both claims are easy to check. The land: every comparable Greenwich lot -- same town, same schools, two-plus acres -- is offered for more than the asking price here, with no house on it at all.

The sales: run these filters on Zillow -- single-family houses, 3,500+ sq ft, 2+ acres, built 1985 or later, sold in the last 12 months. Fifty-five homes. Not one sold below $3.6 million, and the median was roughly $7.5 million. (Zillow flags one apparent exception, 43 Hunting Ridge Rd, but it has only 3,262 sq ft above grade --