Have you looked at the archived ***? Your question has been answered on previous occasions! Just go to the FAQ section in the drop-down box at the bottom of the "Living in Singapore" page. If you go to archived page 2 there is a question entitled "International Schools" - with links to some schools here. Also there is one titled "Local School Fees/deposits". On archived Page 3 there are lots of queries titled "Schools". You are bound to find something of interest in that lot!
I think possibly the cheapest school for expats may be the International Community School which has a Christian ethos (although you don't have to be). It is very small and does not have the extensive facilities that some of the other schools have, but may well be suitable for your offspring. There is a link to it via the "International Schools" faq. The schools don't ever seem to have their fees listed on their websites, they all vary so much with the age of the child and I think they tend to rise each academic year, which generally begins in August or September, apart from the Aussie school.
If you send your little one to a local school you will have to pay a $5k donation to the Ministry of Education, according to the info on this website. Perhaps you could get your employer to cover that? Good Luck.
