Or you can just go to concert and get one from the Edge. My brother was in the very front (inside the ellipse) in front of the Edge.
Right before one of the songs my brother held out one of his Herdim picks and the Edge reached down, took my brother's pick, and then handed him one of his own. Pretty good trade huh?
Coolest thing ever (short of playing on stage with them)
My brother's handle on here is Aughrimfurey if you ever want to chat with him