I looked at the categorical breakdowns and I disagree with several of them. Housing being 39% cheaper in Des Moines is probably close, as is transportation (cost of gas) at 19% cheaper. But in my experience, having moved from Ames to a town 60 miles north of Seattle two years ago, groceries will be a push and utilities will be less. It rarely gets over 90F in the Seattle area (many places don't even have AC because it's not needed), and it rarely gets below freezing. So there's no cooling cost in the summer and much less heating in the winter. Healthcare is hard to say because so much depends on your insurance plan.
Plus the power there is hydroelectric. I remember culture shock when I moved from Pullman to Manhattan KS, and found out my 2 month power bill in Pullman was less than a one month bill in Manhattan. Eeep!