Firestone Complete Auto Care charged me around $80-$90 to mount and balance four tires (purchased online) and rebuild the TPMS sensors. $20 of that is TPMS charges.
That includes lifetime rotate and balance. Firestone also has good quality equipment, so it's a better bargain to me than the super-cheap shops that have old equipment and likely won't offer lifetime rotate and balance.
The rotate and balance is also good at any FCAC.
But now we have DT in my area, so that's my go-to place. They'll match most prices, so I probably won't be buying tires online for a while.