Most of the year, in this underground area, there are tons and tons of live plants you can buy, which is great. However, during Christmas, the underground shopping center that's below the street at the south end of Gosok (Express Bus Terminal) station, near the entrance to Shinsegye Department Store.
Wifeoseyo and I went down there, and we found everything from lovely to tacky (mostly the latter) and a huge variety of things. We found scented candles that smelled like pine and apple/cinammon. We found a christmas tree and strings of lights and wreaths and garlands. We got some christmas tree ornaments and pipe cleaner snowflakes to hang on the walls. In general, what you find at the bus terminal shopping center is a little less... um... K-mart... than what you find in Namdaemun.
And readers, it wasn't a whole heck of a lot, but it made the house look a little like Christmas. And that was important to us this year. And the scented candles even made it smell like Christmas this year, and that was nice, too.
And for your benefit, here are the two places I've found Christmas Decorations in Seoul. If you know of another one, let me know, and send me a location on google maps, and I'll totally add it.
View Christmas Decorations in Seoul in a larger map