HiMart was selling them... not sure if they still are. There are plenty of those around so maybe check there? I also saw them at E-Mart when I lived up in Seoul. Good luck!
A place to buy GoPro camera in Busan
Hey, Emart or Hi-mart may have,I bought mine in amazon and it was way cheaper. A lot of accesories, extra battery for the same price as just the camera in Emart.
I would go online if I were looking for the best cheap action camera out there. You may find on some physical stores but it's always good checking the internet.