Update in 2017- I am not sure if the store is still there. However, wooden moulds can also be found at ordinary Chinese shops selling predominantly plastic products (like pails, storage box, plates, etc).
For those who want to try their hand to make their own traditional mooncakes like lotus paste or kam thui, you would need the durable mooncake wooden moulds.
In case you need to look for it, I have seen a few being sold for RM20 each at this shop located at the top floor of AEON BIG (formerly known as Carrefour) shopping complex:
I have checked with the staff…unfortunately they do not have a phone there. The mould above is placed at the baking section…they also sell baking utensils like baking trays. They also sell pots and pans, glassware, plastic products, plastic storage boxes, gardening items and cooking utensils.
The address is:
Y Pay More Store
F01, F02, F13 Second Floor,
Carrefour Subang Jaya
They allow up to 3 days to exchange defective products.