What are the pros and cons of taking up resales housing grants. Will I need to return if i sell my resale HDB years down the road?

If you planning to buy an HDB and enjoy its grants in the future then you need to 'repay' back some money if you took up the grants for your current HDB. This is to ensure no one can forever enjoy subsidies forever.

You can look at the quantum here
https://www.hdb.gov.sg/cs/infoweb/residential/s...