When I was a kid I used to plan weeks in advance my Halloween costume. One year, I dressed like a poor hunchback and carried a brown paper bag as my treat bag. Otherwise, I always trust my puffy pumpkin treat bag made of plastic to bring home a load of candies. I collected so many sugar treats that I do not recall a year where I ate all of them.
If you are looking for a vast selection of adorable treat bags, Pottery Barn Kids has 15 models in stock. No more plastic. Instead their treat bags are made of soft felt and lined with percale. The regular models cost $12 USD while a few premium treat bag designs cost $19. The Lady Bug tutu costume and the puffy alligator are cute.
Dressing your boy as a pirate like that can be expensive. You could only buy the 6-piece pirate accessories and try to make the attire or vice versa. If you let go the hook that could be cumbersome to carry around, the rest is fairly easy to find at any store that sell toys. In fact, look around your house, you may have some items in the toy boxes or your drawers. The 6-piece pirate set includes the sword, the pirate hat, the belt, the hook, the eye patch and the bandana.