A year ago, the 30 year rate was sitting at 3.66 percent. The monthly payment on a 30 year, $300,000 mortgage at that rate would be $1374.07 If the 30 year rate rises to 8 percent, the monthly payment on a 30 year, $300,000 mortgage at that rate would be $2201.29. 8 percent was considered to be normal back in the year 2000..

http://www.zerohedge.com/news/2013-08-02/why-another-great-real-estate-crash-coming