Bought this, it arrived today - works great to just replace the worn out tubing and keep using the rollers and heads. 3 meters of this should last for years.
In case anyone else would benefit from this info I had to change one of the new tubes this weekend after about a month of use. The other 3 are fine still. Lesson is to be very diligent about making sure nothing (not even a hair) is in the housing that could rub against the rollers and tube.