Time was, new construction usually sold before completion or just a month or so after. That was true in Greenwich and, during the boom, around the country. No longer. Here’s a chart showing national trends but, looking around town, it seems applicable here, too.
For What It's Worth 
and obviously bad news for Greenwich sellers of land or teardowns. Those sellers should expect lower offers.
And here I thought Greenwich was “different” and national trends didn’t apply!
Calculated Risk calls it the “distressing gap”, where new construction can’t compete with the short sale, REO and basic puke job that extisting homes suffer from:
This helps to explain why recent new home sales was the at the lowest level recorded since 1983.
Anyone with money either already lives in a decent house….or can rent an unsold, “new” spec house in nearly any upscale suburb in US
And those seeking to buy the “typical” $250K POS new tract house generally lack secure job or credit to be buying anything anyway…
“Jingle Mail” also generally applies to exisitng, lived-in structures. Let’s hear what scum-bag Dodd has to say about it:
http://www.starkreports.com/2010/02/24/chairman-dodd-on-jingle-mail/