Where to get tyres

I've heard people mention places where they can get a pair of tyres for around $300, as that is about what I've previously paid for the rear alone (and I need both this time) I would be interested in any contact information please.
I need 120/70/17 front and 180/55/17 rear. I would prefer something sport/touring as I do shed loads of Ks and want to get decent life from them.
I need 120/70/17 front and 180/55/17 rear. I would prefer something sport/touring as I do shed loads of Ks and want to get decent life from them.