1991 Submariner 16610 replacement bracelet question

[seabreeze60]

I own a 1991 Submariner 16610 that is in great shape but I think the bracelet is starting to get loose. Three questions:
1. Though the bracelet seems somewhat stretched out to me, when is it time to replace the bracelet?
2. How much does Rolex charge to replace the bracelet?
3. Am I better off going to a Rolex dealer and having them replace the bracelet?

Thanks! Dan