I am a German citizen and US resident (Green Card holder) and will be traveling from the US to Germany later this year to celebrate my parents' birthdays (both "big" birthdays).
I will be bringing an antique book and antique maps that are of special significance for my parents as birthday presents (combined purchase value ~$1500). All items are more than 100 years old and were originally printed in Europe (Belgium, Netherlands, Germany; I've learned that country of origin can make a big difference when it comes to customs).
I've been trying to find out if, and if so how much, customs duty I will have to pay on entering Germany. I've researched the topic at zoll.de and ec.europa.eu, and it looks like the value will definitely exceed my personal allowance, but it appears that customs is a really complicated topic with lots of exceptions and special rules, so I'd like to get a more definitive answer.
Of course, I do have receipts that state how much I paid for the items. However, prices can vary quite drastically, and different copies of the same book/map can be purchased for substantially more or less, so one of the difficulties is that there is no "standard" value for antique items, and I'm a little worried, for example, that the value for customs purposes might be assessed substantially higher than what I paid for. I am not a professional antiques dealer or anything of the sorts, so I don't have any sort of commercial import/export permits.
How would I determine the customs duty that would be due and what additional documentation should I bring?