DDR5 DIMMs and LPDDR chips as in the MacBooks are not the same beasts at all.
A DIMM is 8 or 16 chips (9/18 is ECC), while the LPDDR is a single chip for the same storage. The wild density difference in chip capacity (512MB or 1GB vs 8GB) makes a huge difference, and how a stick can be sold at retail for cheaper than the bare LPDDR chip in volume.
A DIMM is 8 or 16 chips (9/18 is ECC), while the LPDDR is a single chip for the same storage. The wild density difference in chip capacity (512MB or 1GB vs 8GB) makes a huge difference, and how a stick can be sold at retail for cheaper than the bare LPDDR chip in volume.