Either the Monroe or Puyallup gunshows, but you need to be a member and it cost like $50 to join, there by completely eliminating any money you might save by buying elsewhere.

However, the best way to purchase a firearm is to ask at different gunstores how much they charge for an FFL. What this is is simply a Firearms Transfer. If you find one who will do any FFL for $20-$40 or so then he's kosher. Then what you do is go online and look at gun auctions, classifieds, and Manufacturer's websites and find the exact type of Shottie you want, go back to the gunstore who'll do your FFL transfer, give him the $$$ and the shipping and ordering info and have him transfer it for you. You can save hundreds doing this.

Do not attempt this thru Larry's Guns of Olympia, as they will do thier best to hose you...They'll order it for you, but they'll charge you whatever they feel like they can get out of you to get your gun.