hello. Firstly, welcome to the family.

We might not be active chatting here, but we do keep up to date with the latest news here and
https://www.facebook.com/nanoblockfanpage (personal recommendation of mine)
To help you better understand why some kits are available and some aren't, I'll need to do some explaining. In SG, there are mainly 4 ways people get their kits.
1) Official Local Supplier brings in their supplies
- These are limited as local supplier chooses what to bring in or don't want to spend extra $$ to acquire licenses etc.
2) Local importers
- These are either individuals, retail outlets or online shops that ship in the kits from their own suppliers overseas. Usually at a 20% mark up at least from the original price. Prices usually include shipping and all.
3) Online shops + shipping
- From various shops online (AmiAmi, Amazon.jp, auction sites etc). Usually at good, if not cheap prices. Downside is you will have to buy in bulk to justify the shipping cost
4) Friends
- Asking your friend to buy for you when they are in JPN, cheapest way to obtain your kits definitely. But highly subjected to your friend
The place you are looking at is known to us as Toy Brick Station (TBS for short) and is just one of the many local importers. They are a toy speciality shop and you can definitely find a decent spread of kits there (but not the extremely rare ones) but they will come at a decent mark up. If you are looking at Disneyland exclusives, TBS is definitely the best way to get them, apart from asking your friends.