Cost of living is low in Korea EXCEPT for Seoul. If I were living in Seoul I would ask for more than the 2 millon a month, maybe 2.2 million.
Basic food costs are higher as are restaurants and cover-charges etc.
People in Seoul have the best manners and education but the pace of life, the crowds and the dust and pollution keep me away, even for a weekend holiday. Cheju, or Jeju Island in the south is beautiful, clean and subtropical with bird song, pineapples, orange trees and a volcanic mountain but feels a little isolated. One year would be good.

People teach in Korea for several reasons. If you want to make some money you have to:
1. Get 2 million/month standard contract for 120 teaching house a week (no weekend work. It is still not a big salary but cost of living is low in Korea as are taxes.
2. Get the apt. free with the contract.
3. Keep your expenses down. Don't buy a lot of things you cannot take home furniture). Learn to live simply.
4. Do over-time and/or teach a bit privately on the weekend (if allow by law and school).
5. Put your money in the bank at 4% interest. It is quite a good rate and consider this a bonus to your income.
6. Don't leave the country and the apt. till you get your return ticket money and severance pay from your school.
7. Stay healthy.