If you're in Seattle, you're probably getting packages from like Kent or Everett. I don't see how they could afford a warehouse anywhere near the city.
Just a guess - residential real estate pricing and commercial/industrial real estate pricing are not following the same trends.
The reason residential real estate keeps going up is partially due to zoning laws being out of wack on west coast. So just because the price of residential real estate in Kent keeps getting crazier, that doesn't mean the industrial one does as much.