The CMAA has made available a Kyriale extract from the Graduale, with helpful navigation links.
It contains all the Mass settings plus Psalm tones for readings and the Gloria Patri, plus Corporus Christi, fully 160 pages in a format that is far easy to manage that the full Graduale. It is the true "people's songbook" for the Roman Rite. You can easily copy images using Adobe reader. The scan is 300 dpi.
In addition, the Kyriale is available in both softcover ($12) and hardcover ($22) here.