There's a nether portal in-between the S and SE major portals that leads to this nice little Savanna Village. Friendly people, all kinds of crops, and a Librarian holding court in his own hut selling Mending books. A mere 32 emeralds for everlasting* life. Bring extra, if he runs out of Mending books you need to buy other loot to refresh his book handling. Fair.
*not everlasting. If you're busting blocks with no xp return, you don't mend your kit. If you're on the losing end of a battle, Mending won't save you. Be warned.