Nickels are ubiquitous in American life, tumbling around in pockets, rolling under car seats, and emerging from the back of dryers to be used over and over for countless purchases. But these resilient and somewhat humble-looking coins are also becoming costly to produce. Nickel, the coin’s own namesake, has become a prized ingredient in many modern products, pushing the market value so much that sometimes making the five-cent coin costs as much as seven cents a pop.