Hi Kat:
You really have to know what you are looking for. For example, there are some pharmaceuticals that are approved in Germany that are not approved in the USA and vice versa. Similarly, there are alot of Teas in Germany for every kind of illness. I have not seen so many health related teas in the USA, though maybe I didnt look in the right place.
I love Reeses Peanut Butter Cups and although you can find them in speciality shops, they are not really available everywhere...and if you find them they are very expensive. I love those big bags of like 1lb of Reeses that you can buy in KMART or Target for about $3.00. This kind of economy bag does not exist in Germany that I know of. So if you try to find the same amout of Reeses you would pay alot of money. I am guessing around $20, because you can only buy them individually, I think.
In Germany they have delicious Lebkuchen (Ginger Bread Cookies) with a chocolate cover that melt in your mouth. Again, I havent seen them in the USA, but maybe I didnt know where to look.
German Weizen Beer from the Tap is great...but now there is pretty good Weizen Beer in the USA.
As people have said, most things are everywhere. But some speciality or traditional things (like medicines or other health care products, special cookies or snacks) may only be in one country or the other, or only available in specialty shops at a very high price.
If you find one thing that is really very special and not available in one country you can always try selling it on Ebay, but dont try that with prescription pharmaceuticals!
Your German is not too bad by the way!