Fare is not high and it is a nice travel. You are not disturbed by the queue on the border. Sept. Foreigners pay higher fare than Slovak residents. See separate information sheet Danube-travel. They use electronic or mechanic counters.
Tickets are avaliable at the newsagents, in hotels or in machines at most stops.
Tickets from various towns are not interchangeable. Fare on night lines is 10 Sk. They stop only on request. Usually tickets are sold by the driver. You have to use only front door to enter in this case.