In my experience, Amazon and Aliexpress have been great sources for FNAF cosplay items and merch. The quality of the items is often noticeably cheaper than merch you would buy at retail price, but the items themselves are good enough to work for cosplay. Some of my favorite FNAF plushes have come from Aliexpress, too. The review section is your friend—look for reviews that discuss the quality of the product and its accuracy to the photos and description, and you’ll find some great stuff while saving some money.