real quick. how much does it usually cost to mount and balance all four tires?
What do i do if i have an old set lying around. Do i have to pay to get rid of them? thanks.

 

Americas Tire charges up to 25 per tire, which includes stem, mounting, and lifetime balance (free flat repairs and free tire rotations too, I think).

Be careful at any shop, though. Those stupid monkeys get confident and don't balance or torque the wheels correctly. I just caught a guy this week not balancing mine to 0.0.
I had him throw it back on the balancer and he looked like an idiot in front of the whole crew.

 

Firestone charged me $22.50 for all 4 when I had my so3's mounted and balanced with new valve stems. I did buy the tires from them so that may have brought the price down on the labor.

 

My mechanic does it for me for ~30 all four, but it's just a little shop and I know the guys pretty well.