First, you need a work permit. For that you need a "green card", a residency permit. Korean language may be required. Lots of paperwork and time will be required. Made in Korea has not been totally replaced by Made in China; which should tell you wages in Korea are lower than USA but higher than China. So it is likely less or no longer profitable to manufacture there. Bartender may make about equal to USA bartending, sans TIPS!! Korea, like a lot of the world is a no-tipping country. I'd think near chef's wages or waiter.
How much is a flat? Can you live in a one room or efficiency apartment? Can you live with no car, use public transportation, can you adapt Korean way of life. These answers would help answer "Can YOU (yourself) live as a bartender?"
New York is high. Small towns in Texas are not. Moscow apartments are expensive. Central Russia $22,000 will get a nice 2 room. $100K will get a 2 or 3 storey house with banya (sauna), pool, and about 9 "ares" of land (each being 10 metres X10 metres. Each= 1000 sq ft), so 9000 sq ft 1/4 acre land.
Seoul is probably higher than the Korean countryside.