I'm sure you can wear it as is until you decide it needs a service. The problem with that is that if the movement is dirty and improperly oiled, the longer you run it as is the more damage that will cause on parts and when you do have it serviced you will need to replace more parts.
I don't know what each watch smith charges or whom you would send it to, but the price will be approximately $150 USD. It would be wise to use some rolex parts during the service and that will add to the cost depending on how many and which you choose to use.
If I were you I would contact a smith and ask for specifics
I advise you to contact a locksmith before taking the rep so that I understand what I'll have to do? If using original parts to increase the security of the salt service? I would not like to spend too much money, specifically it is a 5 / 5,5k gen rep