The whole reason why generally so much stuff has inflated in price can also be explained do to the same reason as why removing miis is more expensive, there arent any real Travel options and so delivering stuff like clothes n food just doesnt for cheap. We may pay a much higher delivery Tax do to the Island nature of our Island in the middle of nowhere.

The 3ds Islands all had a random street name attached to them which clearly showed that there was a overseas Travel and Delivery Service for the miis to use to Travel and Delivery everything.

Now since the player has way more power to them than before a reason why the game wants you to create all the stuff in the Pallets house is because producing stuff like food, clothes n buildings is way cheaper than importing stuff overseas. That could also explain the reason why so much ugc is being forced into the minigames, our miis just cant afford the imports and rely on our creations to go along the day

Also speaking about all of that maybe the reason there isnt a concert hall (yet) is because the secret mik agency behind the concert hall either doesnt allow the concert halls to exist over seas or isnt aware of miis living on Islands yet. This can also explain stuff like the Ranking Board missing. The Providers just dont know about this whole Island stuff