Does anyone know whether this will become a permanent shop, where it's worthwhile to save points for next year, or are these all the prizes it will ever have?

I'd like to know this too

Most likely these are the only prizes that will be in this shop ever, like Epicon shop. These prizes are specific to Ziara History plot, I doubt they would combine prizes from another plot to this shop.

Thanks for the response!

You're welcome. That's my best guess, have not seen anything official from staff.