A generation ago studying in Australia opened doors. Today, rising costs and falling satisfaction are making international students think twice, and locals feel sidelined.Prefer to listen to this story? Click here.In the hallway of a marble-floored hotel in downtown Ho Chi Minh City, a series of oversized posters show the smiling faces of Vietnamese professionals, now leading companies in the academic fields they had studied in Australia. A software baron. A banker specialising in mergers. A renewable energy pioneer. A fintech founder. A meat importer-exporter.Many of the graduates were there, milling about for the first meeting of a new group…