chadio, in West Richland there is a good shop called Talos Tactical. When I was there a couple of weeks ago I believe they had some of that ammo. And they are not the kind of people who rape the consumer. Give them a call if you can stand the drive from where-ever you are.
In fact they were unloading a couple of big boxes of Magpul G2 and G3 magazines and the prices were under $30 unlike some other shops. Around $25 for the G2 IIRC.
The gunshop in downtown Kennewick is worth a call also. Sorry I can't remember the name.
I haven't been to Spokane since last summer so can't help you there.
“There’s a rattle in my glove box,
A Federal twelve-gauge slug.” – Adam Carroll in song Porter Wagoner