The lowest listed price among them is Sanctum Acolyte's Pylon at 1 silver in the US Auction House.
Next item levels up from Galactic Gladiator's Tome among Armor > Miscellaneous, Held In Off-hand slot: Red Rose (item level 12), Darkmoon Flower (item level 12), Antipodean Rod (item level 14), Ritual Stein (item level 15) and Shimmering Stave (item level 16).
Built from the World of Warcraft client build files and recorded Auction House snapshots.
Where Galactic Gladiator's Tome Fits
Other Items Named Galactic Gladiator's Tome
1 other item in the current build is also called Galactic Gladiator's Tome. Same-name entries are usually a different rank, faction, quest stage or reward track of the same object.
Blizzard numbers items as they are created, so the named items next to ID 265618 (265613 to 265623) were usually added in the same batch as Galactic Gladiator's Tome: the same quest line, zone, vendor or reward set.