It is not a set cost as many might think.
If you have cracked cable housing and loose wheel cones that need repacking with grease then the price might not include this.
I live in Canada but this is the same in almost all bike shops as parts are not part of most tune-ups.
At the very most a good tune-up may include new cables.This is not always good though if you do not know that all,alll,new cables will stretch in a small time and the whole bikes cables will need readjusting.
If you have a few problems try hanging out at a bike shop and asking for some tips.Yet ask them one at a time per every few visits or you will be a freeloader.
People that hang out in bike shops are also a great way to learn as they wish to teach others to show the shop that they know thier stuff.
Most tune-ups cost from 25 dollars to 125 dollars respectively no matter where you live in the US or Canada