There is a Janty/Ovale store in Changwon (not sure how long it's been there). The prices are similar to others reported here (40,000 KRW for a 20ml bottle of e-juice, etc) however if you're in a bind and need something, they carry most everything that comes from Ovale/Janty. Plenty of e-Go attys, tips, eVic setups, and the slim 801-style (not sure of the name?) that e-Go sells.

From E-Mart in Changwon, cross the street at the intersection. Turn left after crossing the street to immediately cross the street again. After crossing, turn right to walk up the hill and it will be 3-4 blocks up on the left, next to the yellow Nikon camera shop.

Here is a Naver link with the address and a picture of the place:

.자담배잔티창원샵: 네이버 지도