I'd say, how broken?
No I don't mean the Cleric. I mean the Wizard.
For instance, really for a Wizard to Persist a high level spell, he needs to go Incantatrix.
Metamagic Wand Grip is for low level stuff, Arcane Thesis is per Spell, Easy is Dragon, Practical is Sorcerer, etc.
Cleric gets DMM(persist) at level 1. No taking levels in the the most powerful Arcane PrC printed, he gets them out of the box as if it were rather than TOing some Red Wizard ideas or w/e.
It would be completely unfair to the Cleric to say he has to deal with a Persist spamming Wizard, and on the same token, a Wizard that is using a secondary method to obtain Turn Undead shouldn't be a measuring stick either. After all, the Cleric is banned from obtaining the Wizard list, why should the Wizard steal the Cleric favored stuff?
So just how high is this bar set?