Don't know what your budget is or if you travel with luggage, but am rather surprised as that's a decent price.

If you don't want to go the bus route, taxi may just be easier, as they are waiting right outside.

I'm a budget traveler, and just take public bus to Metro station even if flying in Biz And not just because I speak Czech - did that in Budapest as well, and speak zero Hungarian.

Here's a link to English version of Ceske Drahy (rail). Interestingly enough they have a link to express airport - train bus on English home page, but not Czech, so I'm guessing it's aimed primarily for tourists / foreign visitors.