At age 55, after setting aside the desired retirement sum, and with $300k in SA at ~4% int p.a., will this mean $1k/month for living expenses?

Hi anon,

Yes, you're right. If the interest rate remains at 4%, you will be able to withdraw $1K/mth out of your interest and still maintain your principal amount in CPF SA. When you turn 65, CPF Life will start and you'll get a second guaranteed income stream. Pretty good deal in my view.