Where to buy tires from?

I'm thinking about buying rims and tires for my car this summer. I just looked at Canadian Tire and for Goodyear Eagle F1 GS-D3 a 275/40/17 tire costs $383 and a 315/35/17 $481 each. That's f--king crazy money to spend on tires.

Where's a good place to buy/order tires from in Canada?
 
Awesome guys, thanks for the help! Now I just have to decide what mods come first...gears, wheels/tires, suspension, PI/cam swap... There's only so much $ to spend this summer :D.

I think with gears it will spin the **** out of my stock 225 tires...