Mark, the pros here will probably give you a better answer. But mileage on tires depends some on the style of riding. But the stock rear tires I am thinking average about 8,000 miles on them. Seems like the stock front tires get a bit more distance on them. There is a thread that TXRIIIrider started where he lists a bunch of competitor quotes and I think he lists the part number, pricing along with the webpage for them. I can't help much on that cause I do the female thing and let my honey take... of the headache of re replacement.
RS