I took a trip to Seoul, Korea recently, and here are some of my diecast finds.
Two Tomicas. I have a couple of Tomica Limited Vintage cars, but haven’t been able to justify the eBay cost of the regular Tomica models after shipping
I found these at Artbox (which sells all sorts of cute stickers and stationery and the like) in the Bupyeong metro station. They were 4000원 each, or about $3.50US.
If you’re in Korea and looking for diecast, note that the few Artboxes I visited in Seoul had no toy cars at all. However, Daiso (Japanese dollar store chain) had quite a few Tomica transformer knockoffs for 3000원.