Shop around a bit. It's possible that jumbo rates are actually LOWER than conventional rates. That was true for us back in late 2013. Might still be true today per this WSJ article:

http://online.wsj.com/news/articles/SB10001424052702303626804579510070672609020

"Some lenders are offering jumbo ARM rates lower than conventional rates, something that would have been unheard of even a year ago, says Guy Cecala, CEO and publisher of Inside Mortgage Finance."

This is a good site to get a rough idea and it's updated daily (obviously it's just WF). Today Jumbo and Conforming match at 4.25%. https://www.wellsfargo.com/mortgage/rates/

It is usually between a 1/4 and a 1/2 a point higher.

If I'm paying 20% down on a house that costs $900k, I'll need a loan of $720k. So, not conforming. How much higher are jumbo rates than rates for conventional loans? This is in Arlington. Google keeps bringing me to a bunch of ads and calculators and I'm having difficulty sorting through the noise.