Comixology has Green Arrow digital graphic novels from DC Comics on sale for $1.99 each, 85-90% off regular price.
FULL LIST
Green Lantern/Green Arrow by Dennis O'Neill and Neal Adams
Green Lantern/Green Arrow: Space Traveling Heroes
The Longbow Hunters
Green Arrow Omnibus by Kevin Smith
Green Arrow/Black Canary (2007-2010): Till Death Do They Part
Green Arrow (1988-1998) by Mike Grell Vol. 1: Hunters Moon
Green Arrow (2011-2016): War of the Clans (DC Essential Edition)
Green Arrow: The Archer's Quest: Deluxe Edition
Green Arrow: Year One Deluxe Edition
Green Arrow: The Rebirth Deluxe Edition - Book 1
FULL LIST
Green Lantern/Green Arrow by Dennis O'Neill and Neal Adams
Green Lantern/Green Arrow: Space Traveling Heroes
The Longbow Hunters
Green Arrow Omnibus by Kevin Smith
Green Arrow/Black Canary (2007-2010): Till Death Do They Part
Green Arrow (1988-1998) by Mike Grell Vol. 1: Hunters Moon
Green Arrow (2011-2016): War of the Clans (DC Essential Edition)
Green Arrow: The Archer's Quest: Deluxe Edition
Green Arrow: Year One Deluxe Edition
Green Arrow: The Rebirth Deluxe Edition - Book 1