Mar 3, 2015 - 5:33 AM
An 8-day Swiss Travel Pass is about 45% more expensive than a 4-day Swiss Travel Pass, so it could fit a 6-day trip as well. Please see here for prices, and here for how to choose between passes.
I would spend an extra day in Zermatt. One day is tricky. If the weather is cloudy you won't see any of the views. With two days, your chances increase. Do go up to Gornergrat if the weather allows, it is beautiful! Of course the weather is a factor for all mountain excursions, so keep that in mind when finalizing your plan. Lucerne offers plenty to do with any kind of weather.
For budget hotels, please look here. For any type of hotel, please check this page.