I've been to Prague and the Czech Republic several times, most recently last May. Things are less expensive, and I generally plan on 750-1000 CzK a day, including a good meal out and an admission fee or two. I rarely use a credit card, preferring to get cash at an ATM. The Raiffeisenbank ATMs are my favorites, because they allow you to select the denominations of your bills (unlike the ATMs at the airport, which seem to issue only 1000 CzK bills). Look for the bright yellow and black signs. I generally purchase opera and concert tickets on line before leaving the US, using the Bohemia Tickets website, and those go on the credit card. The multiday transit passes are a good idea if you plan to use the trams and the metro a lot. If you are 70+ as I am, you ride for free, but should carry your passport to prove your age to the transit inspector (though I've never been asked). In restaurants, instead of a 15-20% tip, you just "round up" to a reasonable number - if the tab is CzK 270, make it 300, etc. And yes, you will need some change for the public toilets, though not the ones in museums and restaurants.