> I never consider interviewing and negotiations a waste of time. It's very valuable practice, no matter what the outcome. Practice is how I get better at both. The more interviews I go on and the more times I negotiate salary, the better I get.

This. I get the impression that most software devs don't make an effort to learn this incredibly valuable skill. It doesn't even have to be haggling, per se. Just asking for a higher salary is often going to increase it by thousands of dollars. It just boggles my mind at how so many people will leave so much money at the table...