Thanks to all lovely members for taking time to respond, I am learning new things and becoming more familiar with the life in Singapore with each response.
With the current inflation, below is the cost I gathered from my research and responses from the group members -
School - $4k per month for Tier 1
International Schools / $3k per month for Tier 2
International Schools.
Accommodation (Condo - 1200 sqft in not so central area) - $5-6k per month + $500 for utility bills
Second hand car - Required approximately $1200 monthly for instalment + Petrol + Parking + monthly insurance and road tax (excluding initial payment required).
$2k (estimated) for monthly grocery etc.
$500 for monthly commute and taxi etc.
Rest all entertainment and travel.