The top shopping destinations as a teacher in Korea are Myungdong, Dongdaemun, and even Gangnam underground shopping center. However, as a girl and a big time thrifty shopper, Ewha Women's University is the place to go.
As soon as you walk out of the exit, you'll notice some shopping carts lined up on the side of the street. Do not be fooled. Keep walking in further and you'll find better deals and a wider variety. Even if the vendors offer you what you think is a cheap price, most likely you will find the same item for less.
Once you pass the carts, you will notice side streets that are filled with racks of clothing. The one thing everyone should know is that most all the stores carry similar pieces of clothing or accessories. Some might sell it for a few thousand Won cheaper. My advice: look around all the stores before you buy anything and then go back to the ones with the better deal.
As you see in the picture, all these stores have racks of clothing lined outside the store with prices as low as 5000Won (roughly $4US). I can honestly say that these are pretty good quality clothing for the price compared to some major stores (ahem, Forever21).
The problem I have with shopping in this district is that most clothes are "one size fits all." Another downside is that most of these stores do not have a fitting room, so it will be impossible to know what it looks like on you until you buy it and take it home to try it on. Along with that, most of these stores do not do exchange or refunds.
As a girl and a shopper, I would recommend all women to check out this area. Another thing I forgot to mention is the CHEAP hair salons. By cheap, I mean 30000Won for a perm or color including a haircut! This is a women's university after all.