This isn't something I'm so nuts about. It's hard to look your coworkers in the eye and say 'I should make more money than you'. Seems like that's a problem there.

OTOH I could see myself saying, "I'm sure I could get $X elsewhere, so I would like to be paid that here. If I'm not paid that here I will likely leave." However, that makes you seem like a bit of a jerk.