The job offer you received sounds good. BUT..

It is very unusual to be offered a 6 month contract with a return ticket. I am wondering why you were offered this? Maybe you are exactly what they want blonde female and young. This is good for marketing and I am not being sarcastic. I know the market in Korea. The other suspecion I have is that the school will fly you in for 6 months (You are Canadian?) and not actually register you as a worker. Canadians can come on a tourist visa for 6 months, Americans cannot. The other possibility is that it is all quite honest. If you don't get a work visa sticker in your passport after arrival you will not be legal.
Reno is exaggerating about the $10 toothpaste (It's cheap there), but pizza is expensive as Korea makes no real cheese or pepperoni. Franchise ingredients are mostly imported. Korean foods are reasonably priced and I like them. Teaching small kids all day is very tiring. It takes a young person. Tomorrow I turn 50 and am going to retire. Woopie!
Most schools ask teachers to do 6 classes each week day. You have fewer. That's good. I suggest you not work on Saturdays. It burns you out.
One thing to remember: Will you be holding the return ticket or have you been promised it after the 6 months are up? The school normally holds it. I'm in China now and forgeting my Korean. Pity. Go to the article called Survival Korean. It will help you adjust. I have a number of lessons for Koreans and articles posted in the beginning months of this website, 2003. You will find them a help.