Eternal wands are what I'd go with. Have him pick up one for spells that he doesn't use all the time, but that could be occasionally helpful. An eternal wand of identify, for instance, isn't in the MIC, but would only cost 920gp, if I've done my math correctly, and would let him identify two items per day without having to pay the 100gp or use a spell or scroll or whatever. And remember, eternal wands work for ANY arcane caster; you don't even have to have the spell on your spell list.
Also, for things he'd use more than twice a day but doesn't want to waste a slot on (shield, mage armor, etc.), normal wands are EASY to UMD - it's only a flat DC 20, and there's no chance of magical mishap. Knock, for instance, could be a good one, and it might even be on his list (I don't have PHB2 on me), meaning he doesn't even need to UMD it.