I've managed to acquire most of them at VERY VERY low costs. 5-6 were given to me, several were bought with various tools at extremely discounted rates. Some open item returns, some non stock. Caught a few "free battery" deals on line and in stores.... And so I have 22. I can easily go through 10-12 in a day. Yesterday I burned through eight 3.0's drilling concrete for anchors. I also occasionally outfit my crews with specialty tools and they need batteries too.