Please see INTERACTIVE RENT / BUY on NY Times on my post above (also copied below for your reference). Here can select all the parameters and make your own calculations. http://www.nytimes.com/2007/04/10/business/2007_BUYRENT_GRAPHIC.html?ex=1178164800&en=030cb4c6466792a7& ;ei=5070
Excellent customisable graph at your finger tips!!