Study Showing the Cost of Renting Vs Owning a Home

Here is one reason to buy now.  Look at this study comparing the cost of owning a home and renting.  This study shows the gap is at its lowest point in 20 years.  Http://www.msnbc.msn.com/id/36650111/

Consider the fact this study was published in April of 2010.  Since that time interest rates have dropped.  The payments on a $100,000 home are now $100 a month less than they were a year ago. 
What if housing prices continue to drop?  You will be in the same boat as everyone else.  If housing prices increase, you are still in that same boat.  Why take the chance on prices and interest rates increase, pricing you out of the chance of owning a home? 

I suspect rental costs will continue to increase if foreclosures and short sales do increase.  If rental costs are rising and home prices dropping, what are you waiting for?