You must be aware that the grant are distributed into your CPF account and not as cash. As a buyer you would have fork out a combo of CPF and cash with only minimum of 5% in cash for that resale flats (if bank loan is taken).
In order to sell the HDB flat all grants must be return back into your CPF account with accumulated interest (with CPF current rate of 2.5%) over the time of your living in the flat. In additional of all the CPF fund you have used for the flat purchase with accumulated interest.
Don’t be taken aback when you have little or no cash earnings left even when you sell your flat even if your HDB flat has appreciated in value. If you need the money to for purchase of your next properly or need cash quickly by selling your flat this would be a hindrance.
Some buyers would rather approach the bank for loan than to take CPF grants as they would reimburse less interest and get higher cash return when they get their HDB flat sold. The currently rate for most banks is around 1.3-1.7% compared to CPF which is currently charging you 2.6% for the grant amounts. Which banks are actually charging you way less if you could borrow from the banks?
It always good to be aware of the in between of the terms and condition before taking up any grants or loan. Do speak to a property agent or banker that you can trust if you uncertain about anything.