I guess the Korean customs (KMAC, 356, etc) will be marginally "easier" to buy just because of logistics, e.g., if you find one on a Korean forum, you can have it shipped within Korea to your friend instead of overseas. But you still face the same problem of locating one / participating on a Korean language forum as an outsider.
In terms of retail, I'm sure you can find Leopolds in specialty shops, probably a fair selection of other mechanical keyboards too, although I'm not sure it's anything you can't order online.
Overall I'm going to have to conclude by saying "no," I don't think having a friend in Korea is going to really help you get any cool keyboard gear you couldn't otherwise get. Probably the most interesting thing is if you could go yourself and see some of the retail shops first hand. Again, you can get all this stuff imported, but it would be cool to see it in shops.
I hope this helps, and disclaimer, I have not been to Korea so I am no expert, just surmising based on what I know about the keyboard market.
