I do have a friend who takes personal group tours around the whole of Taiwan. Though i doubt he collects cards, I may get some info from him on possible sites where the factory is located.
Good luck. I've heard there's over a hundred playing card factories in Taiwan. I found dozens in a casual web search. I was looking for the Legends factory and said to myself, "Well, there can't be that many card printers in Taiwan, right? There's only a handful in the US that actually print here." Sh'yeah...
I did some rummaging through forum posts and i think i found the thread you were mentioning.
http://aethercards.com/discourse/playing-card-plethora/where-to-buy-playing-cards-in-hong-kong/
It is still in PCP though.
Ugh. Oh, well, back it goes... I get easily confused...
Hey!
That Hong Kong post was my thread.
Lol I think I originally put it in STISO but it got moved to PCP XD bahaha.
Verloren was a huge help on that thread and seeing as you found it looks like you read the thread.
I got back from Hong Kong with a HUGE haul of cards. They weren't particularly cheap but mind you though I come from Australia where you can barely buy any variety of playing cards and international shipping costs a lot.
I managed to find 4 card stores in Hong Kong. 2 of them were in the 188 wan chai building; they have similar but slightly different stock. If you're in the Causeway Bay/Wan Chai district I recommend you check em out they have a lot of variety. Price wise they're about 12 USD a deck on average. They have some 30 USD/deck decks too (more limited/sold out ones like Encarded's Tendrils, JAQKs etc). There's also a card store in Sham Shui Po that again has a slightly different range, something unique about them: they have fake jerry's nuggets for about 10USD.
In my opinion the cheapest store (but a smaller range) was in Mong Kok above a Bauhaus. I think the name of the building is Ginza plaza/place or something.
As for your other destinations; can't help you there sorry. But in Japan I think if you looked around you could find some interesting palying cards. I noticed a fair few japanese brands make playing cards through USPC (eg Rilakkuma's, hello kitty, tokidoki ?Bape not sure if they're Japanese though )