Where is the best place in singapore to find cheap diapers?

I think Chinese medical halls sell diapers at a lower price than major supermarket chains. However be careful of the origin of manufacture because for me I use mamy poko and I find that NTUC tend to sell made in Thailand version while medical halls sell the Indonesia one. To me there is a difference in the quality. The cheapest diapers I have gotten so far is always from carousell. Parents who are trying to clear stocks as their babies have outgrown the sizes.