if you are not an avid cyclist and own a bike, how many times do you use it? not often, i think. the same is true of power drills. if you are like most people, you may use a power drill somewhere between six to thirteen minutes in its entire lifetime.nevertheless, supposedly half of all u.s. households have bought their own power drill.as a result, there are approximately 50 million drills in homes across america that are gathering dust. ownership of a product you use for just a few minutes makes no rational sense. besides, there is the obvious cost of the money spent on the drill itself, and there are also the unnecessary efforts of replacing little screw heads, fixing it when it breaks, and then buying a newer version when the current one seems old or no longer works.

여기에서 obvious cost는 무엇을 의미하는 건지 모르겠어요...
갑자기 명백한 비용 ???
이해가 잘 되지 않아서요 .. 친절한 답변 부탁드립니다. ^^