An acquaintance of mine loves tools-not so much as useful items to help him with home repair, but more as a collection to show off in his basement workshop. On a tour recently, I noticed he had a $500 radial arm saw. Now, even I don’t own a radial arm saw, and I work on home building and renovation every day. You might use one if you were a carpenter working on dozens of houses at the same time and needed to cut hundreds of pieces of wood to exactly the same length. But it’s way more than what you to need to say, say, trim a little piece of molding to replace a piece that’s missing or broken. Talk about killing a fly with a sledgehammer. “Why on earth do you own this?