Namdaemun Market is one of the many shopping places people go to in Seoul. We did not spend the time for shopping though and I found the place is suffice for tourists as they were the usual souvenirs that could be bought here at reasonable prices.
There were two types of vendors which ran their business in rows of stalls outside or those that were located in air-conditioned building. I read in blogs that bargaining is not something that is favoured by the traders here but the items put on sale had reasonable prices for tourists already.
There are many other shopping spots in Seoul, depending on what you want to buy. As for me, I don't really shop when I travel so this visit to the market should be more than enough.