Opera is cheap, plentiful, and at least competent.
Two companies, three houses. Same ticket for which the exchange charges 550 Kc can be had for 260 Kc at the venue's box office. For 80 Kc, the truly budget conscious can sit in second balcony which is closer to the stage than in an oversized US opera hall like the Met. Kc gets you standing room, but in almost all cases you will end up sitting in a good seat, because the halls are not sold out and the attendants don't care if you fill the empty seats. Both companies are repertory, meaning in a two week period you should have a choice of 15 or more operas, including something by Mozart in the hall that premiered Don Giovanni.