This grand lady of tango is on stage in two productions at the same time. Diego Romay's production of Tanguera at Teatro Nacional http://www.10tango.com/interior/detalle_agenda.php?idx=492&tipo=1 and in Antonio Cervila's production of Celos at Centro Cultural Borges where she is one of the invited guests for Sunday performances at 18 hs. (30-25 pesos)
http://www.tangodata.gov.ar/home_espectaculos.php gives a list of shows and their prices. The dinner/show at Esquina Carlos Gardel has a top price of 500 pesos, Piazzolla Tango at 400, and Senor Tango at 450.
