I buy tires for my everyday vehicles from Tire Rack online. It's one of Clark Howard's picks. They operate a huge national warehouse distribution operation with a good selection and pricing of quality tires. Their pricing includes a 2 year 100% replacement for road hazards such as cut sidewalls. I have used this warrantee and it works perfect, no questions with a full replacement. Tire Rack does not mount tires they will drop ship them to selected shops in your area. I use a nearby Firestone service center to have my tires mounted and balanced which cost approximately $85 for 4 tires. I live near one of Tire Racks distribution centers which enables me to pick them up and save an additional $40.
I haven't bought any tires for my xfire from them yet but if you search their site you will find them along with a price.