Is Korea expensive than London?

Excuse me, I'm planning a trip and I'm considering two destinations: Korea and London. Could you help me with something? I'm wondering, is Korea more expensive than London? I'm thinking about things like accommodation, food, and entertainment. I'm trying to budget for this trip, so it's really important for me to know. Also, are there any specific areas or neighborhoods in Korea that might be more costly than others? And how about London? Are there any areas that are known to be pricier? Thank you so much for your help. I really appreciate it.