Is the cost of living in Korea so expensive?

I want to come to Korea to work and study. Is the cost of living is expensive?

Welcome to the forum

For living costs try www.numbeo.com

It depends on your definition of expensive and how you manage money. For me, it is lot less expensive than America. Housing, utilities, food, transportation are all less expensive. Medical is lot less expensive.
Electronics are more expensive in Korea. Fruits and vegetibles are also more expensive but taste better.