It should be customs-free, if that's what you're wondering. It's within the EU, so apart from paying the local VAT (I'm not sure what the % is for Germany), which is already included in the price on the site, there are no extra charges. And, since both countries use euros, there are no worries about exchange rates either.
I had an order shipped here (UK) the other day and only had to worry about what exchange rate my bank would charge in order to pay TW in euros. No customs or anything extra.
You only have yourself to blame.