Seattle/Tacoma is a different market then the rest of the state. I'm just across the river from Portland (but I lived in the greater Seattle area for 30 years, I moved down here in 2006) and we have a lot of shops that have been open since day one and still going strong; the problem we have is some little towns just flat out ban the sale in their area, who knows how their cops handle offenders. Just because it's legal doesn't mean they have to like it.after a week here-
the State taxes the headshops 25% upfront for all business costs i.e.salaries, rents, utilities, and of course the "product" What was once assumed to be a pathway to success, has driven out many of the shops. After to talking to my "kids" (42.and50) and their friends, the small business will be absorbed by the large food manufacturers that now control our food "production". The loophole of "medical" weed is being leaned on, as a result of everyone's medical needs.-Sort of like the disabled parking tag, some states (Fla) get a Dr RX and done, NYC you need to go to their DR, submit med history and can still be denied.
In answer to your q Amazon and other tech Companies drive the economy, everything is very expensive. I have yet to meet someone who moved here (City of Seattle) to be close to their source.
My other impression, as the state keeps pressure on, and unless the legal locations can undercut the street prices, it won't be successful. (there is, as the rest of the U.S. easy access)
Price wise, the stores are more expensive than street sales but the stores have better product. We also have a few of processing facilities locally; talk about the impenetrable fortress, those places are the tops (armed guards and all).
As for the Big Box stores, you have to get away from downtown to find some decent prices on anything. Go south to Kent / Federal Way and you'll find a world of difference in pricing on everything. North from Seattle is (was) to uppity for me, same with the east side (Bellevue / Redmond).