I was underpaid for years and I didn't know it
I have found from hard experience that when I lowball my asking pay, I am treated with profound disrespect.That doesn't make a whole lot of sense to me as the usual reason I do so is not to get an offer, but to help out my potential employer, for example by enabling them to hire other people as well.The actual result is that I get kicked in the teeth.  Because of that I ask for what others of my expertise can command, despite that amount of money being far more than what I really require to be happy.