Very inexpensive rooms. Familly run hotel and restaurant. 15 km away from Vaduz, regular hourly bus service to all parts of Liechtenstein.
There are a few hotels in Liechtenstein, but they tend to run on the expensive side. There is one youth hostel (http://www.hihostels.com/...) located in Schaan, but it closes for the winter. You will probably be able to find cheaper accommodation in neighboring Feldkirch, Austria.
Camping Mittagspitz is the only full-service campsite in the Principality. It offers excellent facilities, a friendly reception and a fabulous reasonably priced restaurant. There are three other campgrounds in Liechtenstein. One in Bendern, one in Vaduz, and one in Triesen. All are pretty much full year round.