i'm a grown ass man, i don't buy figures unless they have massive revealing boobs, which includes just about all one piece figures and excludes amiibo entirely.
But either way, you simply ask yourself this.
"Can I access the content in any other way but to buy the Amiibo?"
If you answer is yes, awesome.
If your answer is no, then it's behind a paywall.
And since the extras need to be unlockable right off the bat, theyre all already on the disk, which is self explanitory
Extreme-stretch here, but what you're saying is "xbox live costing money isn't such a big deal because you get a card attached to a piece of paper!"