Portland is already quite expensive; on mean, Seattle is >20% more so. If you have the upper middle class nest egg or sure fire $200k+ annual income, I agree that Seattle offers more. If you have stable middle income, an interest in access to urban neighborhoods, and interest in urban and nearby outdoors, the compact nature and cost of living in Portland is likely more broadly achievable.
ETA: IMO, the PNW "value" play is Olympia. It doesn't have the same immediately accessible outdoors as most of Seattle and Portland, though still quite good; its day trip potential is excellent; COL is notably lower; and you're still relatively easy access to SeaTac and Seattle medical facilities. That said, you need a fairly reliable job or ability to work from home, as it's a limited economy (small pop).