According to CNNMoney, the rate difference between a conforming loan and a jumbo is spreading further apart, with some lenders offering rates more than a quarter percentage point lower.

The following quotes on this issue are from CNNMoney:

"Never in my memory have jumbos been such a bargain," said Peter Grabel, a loan officer at Luxury Mortgage Corp. in Stamford, Ct., with 13 years on the job.

One big reason jumbo rates are so low is because lenders want to attract wealthy clients and hang on to them, said Malcolm Hollensteiner, head of consumer lending for TD Bank. Once clients sign up for a mortgage, the bank can "cross sell them other products, like brokerage services," he said.

That works especially well in these days of strict underwriting standards, according to Keith Gumbinger, a mortgage expert with HSH.com.