Reddit reviews Shiro Amano: The Artwork of Kingdom Hearts

pasting this from elsewhere, but

Fairly cheap options:

• KH Manga (the ones with release dates before 2013 are a different publisher and not as nice quality, if that matters to you), or the art book
  
• Play Arts Kairi is still pretty cheap. (Some of the others might still be available for decent prices, I'm not sure)
  
• Some of the avatar mascot straps are okay priced.
  
• Formation Arts: Kairi, Twilight Thorn, there are some more on the search that are under $30
  
• There's some probably less-than-legit stuff on Amazon, too, if you're okay with that: necklaces, keyblade necklace sets, plushes, decals
  
• You could also check out Etsy if you want to send something custom; "paopu" or "wayfinder" are also good search options if you go that route.
  
• At the Square Enix event the other day, the price list included some official Keyblade keychains for $20 (Kingdom Key, Kingdom Key D, Rainfell, Wayward Wind, Earthshaker) but for the life of me I don't know where you could find those online.
  
  Seconding that keyblade necklaces are a cute gift for pretty cheap, though (there are a bunch of different sets of them available and I'm sure they're all bootlegs, but hey, so are the ones I've had for seven years and they're still cute).