From how I understood it, it should be the price paid x 19 % import taxes. Usually shipping costs are added to the price paid by the customer, which then is multiplied by the above mentioned 19 % (in Germany of course).
However, since shipping is free, shouldn't there be no further costs used for multiplication besides the amount paid?
Besides, @TheOneCalledMichael could you maybe give us another one of those very nice pictures with the pieces on a 55 cm squared board, but from a players view? I think it would be great to see how the pieces, especially the pawns look on such a board.
I just uploaded on 55mm board pictures I shot last week. The longer I look at it, the more I like it. In fact, I'd say I prefer that more than 57mm board. Shot from players view I'll do that tomorrow morning.
With him, what you see is what you get so I never had a reason to return it. I have bought 6 sets from him now. One set I had received 2 pieces with cracks and he replaced them quickly without any charge. He will ask you if you like to order another set so he can save on shipping but if you says no he will send them anyway.
He's quite quick with responding on his chat (website, FB or Etsy) so you can ask him anything.