Staier studied piano and harpsichord in the Hochschule für Musik in Hanover and Amsterdam. He studied piano with Kurt Bauer and Erika Haase, and harpsichord with Lajos Rovatkay.
From 1983 to 1986 he was the harpsichord soloist for the ensemble Musica Antiqua Köln, touring frequently. At the same time he continued his studies in interpretation of classical and post-classical music on the fortepiano. He resigned from the ensemble in 1986 to embark on his solo career on both harpsichord and fortepiano. He became a touring fortepiano soloist, an accompanist for lieder, and a piano soloist for the ensemble Les Adieux. Between 1987 and 1996 he was Dozent for Cembalo at the Schola Cantorum Basiliensis in Basel.