Heard one day near Chicago:
Chicago Center: Southwest Two Four One Three, traffic at your nine oclock, three miles.
Southwest 2413: What kind of a plane is that?
Center: Beech Seven Two Two, what type plane are you flying?
Beech 722: Bonanza F33A.
Center: Southwest did you copy?
Southwest 2413 [other pilots voice]: I dont know why he wants to know – he cant afford it.