Can't Purchase Anything

Well this is a new one...

The money items in the shop won't update from "Buy" to the price, and when I tap "Buy", it says, "Error: Service Unavailable. Either you're not connected to the internet, or there are issues connecting to the application store!".

I know I'm connected to the internet, because everything else, including the ads, work fine.

Incidentally (or not), that Restoring Purchases menace completely disappeared with this happening as well.

I want to add Holly Barrier to my collection, but I can't. I'm just really glad this didn't happen when Missile Toe became available...