FYI GI Joe's and also Jerry's Surplus have gone out of business in Seattle. Also it seems that 2 of the three other locations you listed for Seattle area do not sell your pucks anymore. I had to mail order my last batch from Bradley.
I've had great luck with Amazon.com.
While I'd love to make purchases locally, no one close carries them. I could drive around until I found them, but it's much easier to log onto Amazon, place my order and have them here in less than a week.
And I don't pay local sales tax on them ;D
I'm from Seattle area and I buy the puck from Amazon.com. It's the most convinience place to buy. Plus I think it's cheaper at Amazon.com too!
There is an outdoor store just a couple of blocks south of Safeco field that has bradley pucks. I bought my first pack there when I couldn't wait for Amazon then ordered 4 boxes from amazon. Sorry I can't remember the name but if you drive down there it is right around 1700 4th Ave S.
Good Luck!
BadMoJoe