Do you mean booster seat for car? You can purchase them from Mothercare, for below $100. If you are referring to booster seat for dining, you can purchase online from qoo10. http://list.qoo10.sg/item/IMP-HOUSE-BABY-KIDS-ADJUSTABLE/426166996 $29 http://list.qoo10.sg/item/INGENUITY-BABY-BASE-2-IN-1-SEAT/428638628 $79
Booster seats are available in many places. Have you any particular one you looking for. You can get them at Kiddy Palace, Mothercare, gumtree or Carousell.
Everywhere is available and selling it. You can get it online too. Lazada and Redmart.
thanks