Conquest of Earth by Manly Banister
Airmont Books, 1964
Originally published by Bouregy, 1957
Price I paid: 75¢
Earth’s elusive masters tolerated only one planet-wide organization—the Scarlet Order of Men. Only the most favored of the People could enter the Institute, as children, to undergo rigorous training. Those unfit for the Order became Blue Brethren, servants and guides of the People, aiding and instructing them as loyal members of society, under the rule of the benevolent Trisz.
Killerbowl by Gary K. Wolf
Self-published Kindle edition, 2017
Originally published by Doubleday, 1975
Price I paid: $2.99
Thirty years in the future, the ultraviolent sport of Professional Street Football, a phenomenally popular 24-four-hour-long athletic event, combines pro football with mixed martial arts and armed combat. On New Years day, quarterback T.K. Mann plays the most dangerous game of his life, the game known as Killerbowl!
(Synopsis from Goodreads)