When are you going to be in Germany?
I suppose it would be helpful to ask in advance in the Trading Post or here, when you know which size you want.
In classified ads there are usually just 24" or 29" used qu-ax for about 160-211 AUD. You would have to check if it’s worth it, when you put the 29" as bulky luggage on a plane.
As for new ones, Nimbus are a great choice in the lower price range, which are just about 50 AUD cheaper (VAT deducted) here than on unicycle.com Australia- not worth the hussle in my opinion.