About $10-25 for the parts - about $15 labor if you have a regular person who does lawn and services the sprinkler system also - otherwise probably about $50-100 labor for a sprinkler company or landscaping service who repairs sprinklers to come out and do it. If you know what type you have and can get it yourself, that will cut your labor cost because it eliminates paying for a run to the store for the head if it is not a brand the worker stocks. Also easy to replace yourself, especially if threaded type (many are) rather than glued PVC joint, though that is easy to do yourself too.
