Nobody balances wheels on the vehicles anymore, no matter what you've read (ahem). Not even F1 or NASCAR does that. The rotors are small enough in diameter that an out of balance issue isn't too horrible. Balance the tire/wheel assembly, and you're good to go. We have a balance here, but if I were to pay a shop to do it, I'd ask for a calibrations sheet beforehand. Odds are, it's never been calibrated.