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

Jin Tai Tong, they have a few outlets - Boon Keng, Marine Parade and more. It is a chinese medicine hall that sells baby stuff like diapers, formula, shampoo, toothpaste etc. If you buy from them and bring back the diaper empty plastic bag, they will give you $0.50 off the next diaper purchase.