Singtel legacy plan since dial-up - 500Mbps at 28.90
Nice one, that is good thing about legacy plans which does not increase price when out of contract. SingTel normally does not offer 500Mbps plan to the public but I saw reports of S$34.9 per month for 500Mbps offered with free digital voice.
I am paying S$29.9 per month for Starhub 500Mbps Fibre Internet. Actually it was S$29.9 per month for 100Mbps when I upgraded from 16Mbps Cable Online in June 2014, at that time it came with free Starhub Cable TV Lite and free digital voice, later the speed was upgraded to 500Mbps but they took away free digital voice and then free Cable TV Lite was discontinued in late 2019. I made a mistake of recontract in Sept 2018 when I cancelled the digital voice. Some people got free upgrade to 1Gbps at the same out of contract price of S$29.9 per month, which is a very good deal.
M1 500Mbps may still be of best value since it comes with free digital voice.
Viewquest has 500Mbps plan as well but with CGNAT (no public IP) so you may need to pay monthly fee for the static IP.