Special Delivery, 1917, 10¢ ultramarine, Left Plate Block of EIGHT with Imprint, never hinged, very fine. The two other shades of the issue (grey violet and blue) price their Plate Blocks of Eight at $2500 and $2850 respectively. (Scott E11).
Est. Cash Val. $600 - 800

Obviously very rare. (Image)

Est. $600-800