My pocket watch costs about fifty dollars, maybe more, to have cleaned and tuned up; they usually tighten the spring in the lid too. I really don't know how often a regular pocket watch needs to be taken into the shop because mine has the crystal removed so I can feel the hands. That probably speeds up the time between cleanings quite a bit.

If I added up all the money I have spent having it cleaned, I could have replaced it several times over the last twenty years, but it's an old friend now.