apparently i'm from munich as well. The world is a village i know.
At the city centre there are 2 shops that have ukuleles.
1. Hieber Lindberg, they had very good brueko ukuleles, ortegas lanikais and some others
2. the music store im tal, i forgot his name. But I think he has only mahalos, still worth a try
Secondly,
There are many good german/european ukulele online stores
That will prevent that the uke is stuck up at the custom office and that you will have to pay 50 $ shipping.
And you will have warranty as well.
In the low-budget section, 50-300 €, no way goes around brueko ukuleles. for 90€ you can have a good sounding, solid wood, high quality ukulele. The Ukes are being built in Germany, i think in Swabia
They have an online shop:
http://ukuleleshop.com/
Further recommendable German Online shops:
http://www.ukulele.de
http://www.hulaparty.de
http://ukulele24.de
I would also invite you to check out the homepage of the German Ukuleleclub. It's really informative and there are many ukeplayers who are active in their forum.
http://www.ukulelenclub.de
I think you got enoguh information now