Interlaken has a wide range of hotels in different categories.
Homepage Tourist Office Interlaken: www.interlaken.ch
Here are a few recommendations, especially for groups:
Prices start at CHF 43.00 pP (group accomodation for 6 persons, shared toilet/shower on hallway)
Private twin bedroom with en suite bathroom available.
sheets (all beds made up) and a towel
private lockers in all rooms
use of self catering kitchen: 24 hours
high speed WiFi in the whole building and all rooms
free entry to public in- and outdoor swimming pools
free Minigolf and Tennis
free use of public busses