http://wiki.eqemulator.org/p?Experience_By_Level
The splitpaw scroll quest gives 1.1%, or 2000000 exp at 52, for reference. A dark blue NPC gives about the same experience at 52. Exp multipliers are not applied to quests, so this assumes you are a human wizard. An NPC that is level 45 takes approx. 5 nukes to kill as a wizard, with 5 minutes downtime inbetween kills provided you are killing a single NPC.
Someone else do the math because i'm lazy.