I use a compound interest calculator
if starting off at 150k CPF SA+MA at age of 35, every month add $500 (assume CPF OA is used to pay properties), after 20y, it comes out to half a million
even assume dual income, it will come to 1m
1 million 20y later probably has the same purchasing power of 500k today
20y later, buy one car probably 200k already, one HDB probably 1.5m, MM condo can be 2m, one plate of chicken rice min $6 
giving extra 1% interest for the first 60k in CPF does help ... but what they should do is give extra 1% interest on the minimum sum instead
Ride at your own risk !!!