Some places I've had it done for free, some charge upwards of $100.
My best advice would be to call around, or if you have a place in mind that you would want to fix it once it's been looked at, call them ask for an inspection. They will ask what's going on with the car, and normally tell you to bring it in to them.
Most good places though will do it for nothing, in hopes of getting the real business from you.