The expensive cost of living depends on your contract. Most Korean contracts come with free housing, within 10 minutes walking from the school, and thus the teacher does not waste money on commute / scooter (like Vietnam). Cheap groceries are also available off Gmarket.

My fixed monthly expenses is around $150 USD (groceries + phone + utilities). I honestly would had gone without the phone and just used wifi hotspots but unfortunately my school made me get a phone (otherwise I could had pocketed another $300 or so at the end of the year).

Cannot tell me Vietnam is cheaper than that when I subscribe to many TEFL channels and the teachers say they're paying $300 - $500 USD for their Vietnam apartment. I don't have that expense and the typical Korean contract pays better than the typical Vietnam contract.

Granted the social aspects of Korea are probably inferior to most countries. Confucian culture puts the outsider at the bottom of the social ladder (even though Korean people abroad tend to be the underclass in Japan and sometimes in California).

Confucian culture is pretty much only left in Korea nowadays. China lost theirs to Communism and Chinese people tend to love foreigners, by comparison.