Well, I'm sure if you write an email to the "Pythagoras Kepler Schule", they will tell you where you can buy a such one from the US. They will surely also understand english.
From the page indicated it follows, that the tubes they sell are 62 EUR (about $100) for 1m (3 feet) and 87 EUR (about $140) for 1.5m (5 feet).
What I personally think is really a pity, that these tubes are made out of metal. Because Victor himself said, they should not be made out of metal (e.g. in the book "Unsere sinnlose Arbeit") due to the very good thermal conductivity of metal which is contraproductive to the energizing vortex inside the tube. He suggested using a good wood for it would be best.
But it should still be much better than the usual tubes for the water...
Love to all! Shanti