You also can't import just lowers of any of the "otherwise prohibited" models, eg. 19, 23, 32, 26, 27 etc. You can import the whole pistol with the Canada-legal barrel, but anything less and you will have troubles. Costly, frustrating troubles.
Upper on the EE is priced according to seller's hopes, but only the buyer will set the price eventually. There's an ugly G26 upper with some sort of flames on it waiting for weeks for $425. If you had factory new parts, your inbox would be full at $425.
What do you want a lower for? Just a dedicated .22, with one of the conversion kits on it?