Should have come here first as I bought 2 tickets on OeBB for Budapest-Wien next month on a Hungarian EC. Only consolation is that since the timetable hasn't been released and MAV is not selling tickets, we got FC tickets for EUR 21 each. Connecting at Keleti (from Eger) so Regiojet wasn't an option even if i had looked.

FWIW, track work in Hungary should be finished later this month (I hope). Right one has to make their own way to Kelenfold for bus to Tatabanya before boarding the train there. Adds 40-50 minutes or so it seems.