CELSurplus in Alberta has an M7 bayonet (which they mistakenly refer to a Canadian C7 bayonet, but of course I have the real deal (made by Nella, marked C7) and can comment on it, since the one they show has a different sheath and a black blade, mine is a grey stainless) for $90. Unfortunately you have to buy it online, but call the guy up and you should be good.
http://www.celsurplus.com/