Sacred Stones OST has been released as DLC. As you can see, this OST is almost a separate record, not a sound recording in the game. (Of course, a lot of motifs from the melody of the game.) This record is a regular record that goes up to each streaming site. But it's cheaper to buy with DLC :) This is a sample song : https://www.youtube.com/watch?v=rD1OJtTH4G0