I second this!
You will save money by bringing your own pirate costume for the kids, for sure. At the time we went, there were only 2 available for boys: Jack Sparrow and a Skeleton Pirate. Both were around $70 each. I believe there was one for girls, the pink one, and then of course a mermaid like one.
Like most CM's at Disney, be ready for all the CM's to be in character the ENTIRE time. They will laugh and joke with you if you even attempt to have a normal conversation with them or ask questions. LOL. Just an FYI.
Definitely do Photo Pass or Memory Maker because they do a GREAT, FABULOUS job at taking pictures afterwards.