Wish by the RAW

[CASTLEMIKE]

Tome of Clear Thought +5 is a 137,500 gp magic items that basically take 5 Wishes to make.

Although there may be a few games where a DM wouldn't twist that Wish which excedes the capability of a standard Wish and is by default a greater Wish effect most DMs would IMO bringing along the Lich and Vampire cohorts or other guardian of the Tome or bring the PC to the location of the Tome usually with their gear as per the transportation effect of the Wish.......

I had a DM who said it was common Wish lore not to shapechange into a Zodar to use the Wish ability....More Zodars, Misfortune....

The best way to get Wishes in game IMO is the Thaumaturgist PRC -1 with the Planar Ally spell and paying a Efreeti or Noble Djinni both 10HD for the short term service with a Cleric or an Arcane caster with the Arcane Disciple feat Summoning domain for minimal experience cost and the service fee at L11 or L12+.