Jan 11, 2012 - 1:50 PM
Unsure whether it is of any help, but you can travel the two lakes Thun and Brienz on a Lazy Monday at a reduced rate around 28 CHF. Realistically you would struggle get around both lakes, but there are areas which are well worth a stop. If you are staying in the interlaken area you will probably be entitled to a guest card allowing free bus and some train travel within the local area. Harder Kulm is also an offer with the guest card (2011)
If on a tight budget, Harder Kulm cable lift at interlaken is a good 10 CHF round trip with a good circular walk at the top , and of course somewhere to get drink/food, although I would have a coffee at the Lake brienz ticket kiosk at Interlaken near Ost train station.
the falls opposite Brienz is a worth a visit and the funicular travels from the where the boat comes in. If you time it right you can travel on the exquisite old paddle steamer.
Again a lovely walk up the path of the falls, with super views across the lake.
Hope this may be of help