212 E 47 is a 2006-2007 condo conversion built in1979. Current for sale listings there are at $1,528 per ft² avg and $967,833 avg total price;
310 E 53 is a 2006 construction. Current listings there have an average $1,701 per ft² price or $3,369,750 avg price.
From what I've seen, brand new developments with good amenities are starting at $1800/$/psf for lower floor apartments. Let me know if I could be of any further assistance.
Elena Ravich | Associate Broker (Licensed as Yelena V. Ravich)
250 Park Avenue South, 12th Fl | New York, NY 10003
C 646.593.7207 | eFax 917.262.7045