I was looking for Cokin P121/P121M graduated ND filter at Cathay Photo. Unfortunately they only have P121L (one stop ND2) in stock. Their price is S$28. (It costs U$23 or 24 at B&H Photovideo in US.)
I believe Cathay Photo is the official resaler of Cokin. Anybody knows which other shops in Singapore might carry Cokin filters?