Travel Insurance from Priceline or any other airline or travel service (hotwire etc.) only cover very specific events that would cause you to cancel, i.e. an illness (your's not Bono), becoming unemployed, a terrorist act in your departure city, a natural disaster that disrupts travel in your departure or destination city etc. Unfortunately, a concert being cancelled in your destination city is not one of them. I guess you could argue that the concert cancellation is a natural disaster or act of God, but you might have trouble convincing the insurance company of that.
So in this particular case Travel Insurance wouldn't have helped at all.