You know you're doing something right if you can present something that increases a PC's stats in such a way that they are loath to accept it. Attach it to something so horrifying that it overcomes the player's natural greed.

Apply this to all the treasure you hand out, if you can.

Transcript

General Grievous: I shall perform the surgery myself.
General Grievous: Minions, trepanate this droid for brain insertion.
R2-D2: What?
General Grievous: The cerebral cortex of the bewhiskered one 
Obi-Wan: What?
General Grievous:  and the reptilian amygdala of this... irredeemable fashion disaster.
Anakin: What?
General Grievous: Together they will make this puny Alderaan-Army can into something worthy to polish my left foot.
R2-D2: What??!!
{R2-D2 goes berserk, spinning and zapping and spraying gas and sparks}
[SFX]: Zzzap!
[SFX]: Szztz!
[SFX]: Zzzap!
[SFX]: Whirrr!!
[SFX]: Szztz!
[SFX]: Zzzap!
[SFX]: Whirrr!!
[SFX]: Pssshh!
R2-D2: I don't need brains! I function perfectly the way I am!