Hi Im currently in gstaad its a fantastic place tgere are plenty of walks and otger activities to do that dont cost the world there is an outdoor pool near by in saanen that cost 9 francs per adult but you can also get a family ticket.
Regarding tge guest card its if your sraying in a hotel you can get tge easy access from them its well worth it.
There are some restaurant that are extremely expensive but like anywhere if you shop around there are some that are well priced.
It should be fairly warm in august so walks rides swimming toboggans mountain lakes all good activities to consider.
Enjoy your stay gstaad is a great place .
Excuse the spelling fast text on phone