Where to buy cheap Lego Duplo?

if you're looking for original duplo, then you can wait for OG or metro 20% storewide sale which includes lego items as well. sometimes toys r us and robinsons will have some duplo on sale as well, but it's not the whole range. if you're not fussy, you can buy the imitation ones sold at pasar malam, kiddy palace or taobao.