I had an Italy T-shirt jersey (a T-shirt that looks like the jersey but is cheaper) and a US T-shirt jersey.
I'm American-born, but Korean ethnically.
You can buy whatever jersey you want, but people tilt their heads sometimes if it's not your country.
http://www.jennynfljerseys.ru/
You have the freedom to wear whatever jersey you like..
Wear a Germany top, why not?
No buy anything you want. It a fun.