Go shop around, learn a little German, be willing to buy used. You'll get a much nicer bike for a limited budget going used vs. a low budget new bike. As mentioned, check around on base and with other Amis around to see what is kicking around for bikes.
AFAIK, Germany has road maps...
Also: it's more properly spelled "ya'll" in my experience, since it is a contraction.
All the German bike shops I ever went into were also very cool shops.