NAKHON SI THAMMARAT, Thailand -- To the list of speculative market bubbles popping around the world, add this: Thai religious talismans.

Last year, prices for the small discs inscribed with an ancient mythological figure soared as ordinary Thais -- some hoping for good luck, others looking to make a fast baht -- forked over big-time. In this southern fishing town that is the center of the talisman industry, Saranya Nimitsomsakul supplemented her income from trading second-hand fridges, clothes and washing machines by buying...