I saw your question elsewhere about visiting the Alps along your way. Mürren (near Gimmelwald) is a bit off your path, but they have a wonderful Dorffest the first weekend of August, with a parade, decorated cows, music, yodeling, etc. This year is is August 6-8. Here is a link with photos from last year's festival:
http://www.jungfrauzeitung.ch/artikel/96784/autoplay/
We inadvertently ended up in the middle of this on our first visit to Mürren a few years ago, and it was great.
There are places to stay around there that are not particularly expensive. Try Chalet Fontana in Mürrren, or any of Rick's recommendations in Gimmelwald. These would all be fine places to stay on your own.