Can't speak to your other question, but an AUTHENTIC M-9 like the one pictured, or Marine Corps bayonet, (the USMC uses one that is very much like a Ka-Bar knife these days), are pick your poison for about $100.00+ shipping from an internet retailer like Knife Center of the Internet.
You can get knock off M-9 bayos for about half that if you don't mind using/relying upon Chinese mystery blade steel. The real deals are not made out of cheap stainless steel.
M-9 Bayonet by Ontario Knife Co.
USMC Bayonet by Ontario Knife Co.