The ExFighter

[Kelb_Panthera]

I assume if you are killing the fighter by means of grease and glitterdust, then he isnt even allowed resistance items

obviously, at any equal level, a wizard beats a fighter, the question is what is the minimum where a sound trouncing (one that does not set the timeframe or require incredibly lucky rolls) happen

Even as low as 5th level the scroll of force cage is not an entirely unreasonable expenditure of WBL and a 5th level wizard with no CL boosts still has better than even odds of activating that scroll. Once he's trapped in the force cage, the wizard has hours to either spam spells at him, drown him in summoned minions, or any of a dozen other means of taking him out.

By taking away the fighter's ability to aquire items that do something other than add numerical bonuses, you've completely hosed him. Even just a rod of cancellation negates this tactic but without that or some other means to either break the cage or dimensionally travel outside of the cage, there's nothing the fighter can do to counter. At least nothing short of producing a DC 120 escape artist check.

Edit: just remembered the fighter can take martial study (shadow jaunt). This pushes the wizard back up to level 7. The wizard cages himself, the fighter shadow jaunts into the cage to get to him, the wizard D-doors out leaving the fighter trapped. Alternately, the fighter doesn't shadow jaunt into the cage and the wizard is out of reach while he uses his magic to attack as best he can.