In the unassuming town of Warminster, Pennsylvania, there exists a treasure trove so vast and so affordable that locals have been known to whisper its name with reverence: Holy Redeemer Thrift Shop.

Delicate lace collars and handkerchiefs speak to an era of refined manners, while bold polyester shirts from the 1970s practically shout across the room. Wedding dresses with impossibly tiny waists ...