Yeah, 64GB is now 300usd where i'm from. While the fiio x5iii is around 380usd.
With an ipod no need to get external memory.
With fiio no need to get cases.
*With an ipod no option to get external memory
With a DAP that accepts two cards you can have up to around 400Gb. For those of us who can't justify spending so much on cards, you can have a bank of 64Gb cards and swap them as you wish, offering basically limitless storage.
You also get a device where you can organise your files as you see fit and are not tied to iTunes. This freedom alone makes the choice a no-brainer for many (myself included)