I used to buy the winchester white box 40 round value packs from walmart, those were an awesome deal and surprisingly accurate! Now the cheapest place to find .223 (that I know of) is the Army Navy store on Agricola St. in Halifax. They sell 55gr. soft point Prvi Partizan for $13 + tax if I remember correctly, I've been loading my own for a while now so it might have changed, I know they raised the price of 9mm by $1 over the last 6 months.
If you think you'll use 1000 rounds then buy a box of Remington PMC to see how they work in your rifle and if it works well buy some from Canada Ammo, its the best deal going. It'll cover plinking ammo for quite some time and there is always Prvi for shooting coyotes, if you can't use FMJ's on them in NS that is... I'm really not sure about the rules.