The way to retire rich is simple.
First buy cheap BTO and after 20 years you can pay off the loan.
Then you can rent out your whole unit to FTs.
But for this to work, we must support the 6.9m population or even more, but must ban PRs from buying our resale HDB flat, so that they cannot buy but must rent from you.
Then you retire in 3rd world cities, such as KL, Bangkok, Chiang Mai, etc. Your flat can easily rent out at $3.5k a month. This translates to RM9k plus in Msia. If in Thailand, even more cheaper. Retire like a king in 3rd world cities KL, Bangkok, Penang or Chiang Mai. But you must take care of your safety, don't take for granted.