in 2006 we joined the OAV (Austrian alpine club gb section) and that got you preferential rates at the huttes , there were 2 routes , the high route as described above and rucksack route which was a lower level but still exacting journey. The huttes were a revelation , would definately recommend.
Actually, this is about what's now generally referred to as the Stubaital Höhenweg, or Stubai High-level Route, which was originally called the 'Rucksack Route'. ie the lower of the two routes. Both routes visit the Franz-Senn Hut. The higher one involves glacier crossings, which makes it hugely less popular because most people don't feel competent to cross glaciers. The 50 Euros a day I mention assumes Austrian Alpine Club membership, which also provides valuable rescue and accident insurance.