I don't bother trying at the gun shops, I'm not good enough at it and if you have ever witnessed an aggressive haggler at work it can be a little embarrassing and silly looking. I don't generally care what people think about me, but I'm not gonna make a clown of myself by trying to talk the shop down $20.
I have asked them to throw in a box of ammo and that went good.
Big box places there's no point in even trying.
Private sellers yeah I will haggle. I have cash and they want more money than a shop will give em. Sooo... There is room for it.