Just to give you an idea of how difficult it is to estimate the price -

I live in Paris France and there are lots of professionals and Nikon has set up a service desk in the center of the city. You can talk to the techicians and if it's possible to make an adjustment on the spot then they do it, usually for free. That's good service.

If a real repair job is required then they send it to the service center in the suburbs. That's minimum 3 weeks and $250 - I paid $700 to get one of my lenses serviced. But afterwards it was like new

These are French labour costs. You live in an area where labour costs are much lower so you'll just have to ask.