I will never need for my offspec unless its going to get DE'ed or noone needs it. Then I will, and I always ask first. Hell, I'm the guy who even passed on a trinket once (price of progress) to the pally tank (he did ask) because I already had a 463 trinket (vial of viscous blood). Sure price of progress is better than the vial, but I didn't care, I helped someone get something they needed. I don't care if I never see them again. Being nice shouldn't require any external reward to be appealing. Its called . . .well, being nice.