When you visit an international school, you might be given only 2mil won a month for a kindergarten position, may be because of international insurance and Korean health plan and that they would provide a flight home every year and the housing will be expensive with security. But these points are not valid. This is really low; rather you can make more in regular Korean public schools.
Talking about security, he will be an old man in charge of garbage bins. Flight home is standard, and what good insurance going to do you, unless you seriously get hurt. The reason for the low pay would be because the school might only cater 3, 4, 5 year olds in low numbers.
At a university you can make more money with longer vacation. But if salary is your only consideration, try to find out the kind of hours they expect from you, their class size, number of class per day/week/month, what kind of resources they have. Find out if you get the salary on time, about the accommodations. Find out if you will have to travel to work and if so how long.
Low salary might be due to the fact that it’s kindergarten, if it is an IS registered school that offers IB and AP at the higher levels.