Getting there by train from Austria or Germany takes long. Shuttle services offer trips at reasonable prices. There are some that offer very low prices to begin with, but when you "book" , you receive much more expensive offers.
Some shuttle services do not even publish contact information on their website, email and or telephone number. I did not know this is possible. I do like to know, who am I dealing with before I fill out a booking form.
Shuttlebus.cz shows a telephone number. The owner of the small company firm answered himself.
You see reasonable prices on the website and get that price and better prices, when more people happen to be on the same trip.