At the risk of , the NYT today has an article on "Rent vs Buy" . It is accompanied by an interactive calculator which looks better than many I've seen in the past.
"Methodology
The calculator keeps a running tally of the most common expenses of owning and renting. It also takes into account something known as opportunity cost — for example, the return you could have earned by investing your money instead of spending it on a down payment. The calculator assumes that the profit you would have made in your investments would be taxed as long-term capital gains and adjusts the bottom line accordingly. The calculator tabulates opportunity costs for all parts of the buying and renting situations. All figures are in current dollars."
Link to calculator
http://www.nytimes.com/interactive/2014/upshot/buy-rent-calculator.html
omni
"Methodology
The calculator keeps a running tally of the most common expenses of owning and renting. It also takes into account something known as opportunity cost — for example, the return you could have earned by investing your money instead of spending it on a down payment. The calculator assumes that the profit you would have made in your investments would be taxed as long-term capital gains and adjusts the bottom line accordingly. The calculator tabulates opportunity costs for all parts of the buying and renting situations. All figures are in current dollars."
Link to calculator
http://www.nytimes.com/interactive/2014/upshot/buy-rent-calculator.html
omni