Where is load-leveling data stored on a MicroSD card?
SD cards comprise a memory store (usually NAND), and a microprocessor to manage the memory, maintain a physical-to-logical block map, and present the interface to the host. The logical address space has fewer blocks than the physical store.  In addition, an erase/program (EP) cycle count is maintained for each physical block. This ultimately enables wear-leveling and bad block management.

Only the logical address space is presented to the host.  Reformatting an SD card (say as a FatFS) will not change the internal bad-block flags or EP cycle counters.

What actually happens under the hood is manufacturer- and card-specific, and most likely a guarded trade secret.  Some manufacturers (especially, of industrial grade cards) provide proprietary tools to monitor the health of their devices, and may even allow low level reading and resetting of flags and counters.

Cost determinants include underlying NAND memory type (SLC is more expensive than 3D), the logical to physical block ratio, and the availability of management tools.