Just returned from doing Unplugged at it was a blast!!! Everything was amazing and I’m sure you’ll have a great time.
In regards to money, I would recommend doing this. In Switzerland, you’ll only really need money for drinks and maybe some gifts if you need them. The drinks at the bar are reasonable but on the high price side I’d say. It’ll be cheaper to buy drinks from the supermarket in town or at the camp site. 5-6 francs per large beers pretty standard. So it depends how much you plan to drink.
In Prague, I would just take money out of a cash hole when you’re there. Spending for everyone is different on budgets. I managed to spend less than 70 quid a day on full days with food, transport and drinks.
We’d stock up at breakfast (toast and muesli) and most places you’re so busy trying to fit everything in, a quick sandwich on the go is pretty cheap.
Enjoy the trip man, it’ll fly by