I don't remember if I posted about it (probably not); RB's album "Chopin Polonaises" has "Chopin's Waltz Op. 34-2" as a bonus track which is available from iTunes Store and other on-line shops in many countries. Usually you need to buy the entire album to get the bonus.
All the albums that he released for Deutsche Grammophon has a bonus track, buyable on-line.
1 Chopin Mazurka Op. 50-1 (Chopin Complete Preludes)
2 Mozart Sonata in C major k.545 1st movement (sonatas-haydn, mozart, beethoven)
3 Chopin Mazurka Op. 17-4 (Chopin Piano Concertos)
4 Debussy "clair de lune" (Debussy Szymanowski)