I think this is very dependent on the vet. I have seen vets that are in a practice with lots of other vets and it is more big business like and they charge FOR EVERYTHING. They encourage every annual shot known to man without explaining what is necessary and what is optional.
The one place I went when I moved to Ohio basically charge $15 to walk in the door. ON top of that their office visit charges were pretty high. The vet that I see now is great. He is a sole proprietor of his office and has many times not charged office visits when I have had problems that made me come in week after week. I respect his opinions and sometimes suggests some expensive holistic stuff but I know he is suggesting it because he believes in it.