Before I came to Korea to teach, I was like anybody else in my situation. I read every imaginable article and blog, and watched ALL the videos on YouTube. One of the big topics I often wondered about was how much groceries and toiletries would cost. Well, it's been one full year that I've been teaching in Korea and I have a good idea of what and where to buy the things I like and need. It differs for everyone, but for my needs I have certain shopping habits now based on availability, price, convenience, etc.
Here's a list of prices for some of the items I buy and what may be interesting to you. They are based on the two main stores I shop for groceries and toiletries at - HomePlus and Costco. HomePlus is one of the major chain retail stores in Korea. It's very similar to target, but on a smaller scale.
HomePlus: