
lemeres |

Agile weapon?
What is he is strength based?
....what, why is everyone laughing?
Anyway, how about throwing an intelligent item with some useful spells? Even if it is an item that he would use for its intrinsic value (example: a weapon weaker than his current weapon), it is always nice to have an item with a few options. With the prices to add a level 3 spell 1/day or a level 2 spell 3/day within your price range, I am sure you will be able to find something he will appreciate.
Otherwise, we would need to know more about his build and current gear to give good advice.

StreamOfTheSky |

Well, technically Agile would stack with Shadow Blade. SB adds dex to damage for SH weapons, on top of strength. Agile replaces the str bonus to damage with dex. So it would be a nice bonus for him.
Other weapon ideas:
A Shadow Hand discipline weapon. The +1 market price special property that gives you a +3 to hit when in that discipline's stance or using one of its strikes -- I assume w/ Shadow Blade, he's constantly in a SH stance.
Living Chain (from Magic Item Compendium) with another +1 property added (like Shadow Hand). You use the 3E version of spiked chain, right? Right?!
Other items from MIC:
Vest of Free Movement (12,000 gp): Get Freedom of Movement for 3 rounds as a swift action 3/day. Part of Fleet Warrior's Array set.
Sandals of Light Step (9000 gp): +10 ft enhancement to speed, ignore difficult terrain; 60 min/day of water walking you can split up among allies. Part of Fleet Warrior's Array set.
Blindfold of True Darkness (9000 gp): 30 ft Blindsight, but blind otherwise.
Crystal Mask of Visual Insight (10,000 gp): Unlimited use; as a swift action ignore effects of concealment (presumably including total concealment) for 1 round.
Gloves of the Balanced Hand (8000 gp): Gain TWF feat. If you have it, get Imp. TWF instead (and can then use it to qualify for Greater TWF).
Mantle of Second Chances (12,000 gp): Immediate action reroll 1/day.
Bloodclaw Choker (12,000 gp): +2 Constitution, and 2/day as a swift, regain a Sorcerer spell slot of up to 5th level. Wearing it does 1 damage that can't be healed till removed, and regaining a spell slot does damage equal to 2x the spell slot's level (can be healed). Part of the Instruments of the Blood Gift set.