Your post reminded me of my most expensive coffee experience, which was in Korea too. It was further back in 1993 before espresso-based coffees were a thing in Korea, and what was served was either instant coffee or brewed coffee. At Lotte Hotel, I ordered a black coffee, and was charged W23,000. It came with a little caddy with 2 glass containers - one for sugar and one for "prima", the powdered creamer mix. Considering the price for a dolsot bibimbap at the time was around W2,000, this was an incredibly expensive coffee. In today's terms the coffee was about USD$100!!!!!