1goodcatch,
The only relatively cheap feeding frogs you can legally buy in Ontario are the African clawed (about $1 a piece for small ones). For an aro bigger than 8 inches, though, this is not sufficient. For a while I raised my own Leopard frogs. That's a route you can take but you're in for some work.
i bought a few frogs recently...excited to feed my aro
i heard of crickets being pretty nutritious for aro's but be warned...its like crack for them, hard to get them off it once they eat it. mine starved for a few weeks after i stopped feeding it crickets.