GAIBERG, Germany—Shopping for pain reliever here on a recent sunny morning, Ulrike Berger giddily counted her coins and approached the pharmacy counter. She had just enough to make the purchase: 31.09 deutsche marks.

"They just feel nice to hold again," the 55-year-old preschool teacher marveled, cupping the grubby coins fished from the crevices of her castaway living room sofa. "And they're still worth something."

Behind...