My own personal experience, because I'm now doing National Service, and I'm using the mobile phone data most of the time.
Last week usage - Singtel
19 Aug 0.97gb
20 Aug 1.01gb
21 Aug 1.62gb
22 Aug 1.31gb
23 Aug 1.07gb
24 Aug 0.29gb
25 Aug 1.4gb
Total = 7 days = 7.67gb
Last week usage - TPG
23 Aug 0.63gb
24 Aug 0.53gb
25 Aug 0.04gb
Total = 7 days = 1.2gb
Singtel + TPG
= 7.67 + 1.2
= 8.87gb
7 days - 8.87gb
1 day - 1.2671gb (5 s.f.)
30 days - 38.013gb
*note: I was at home on 24 August, using the Singtel Home Broadband (Wi-Fi).
With provision for 25% spare capacity,
Amount of data needed to survive for 30 days with only data,
38.013 × 1.25 = 47.51625gb
Or 50GB.
M1: $45 for 50GB
M1: $41 for 40GB and unlimited weekend data
Starhub: $30.4 for 65GB
If got unlimited weekend,
Means 8 days of unlimited data,
22 days = 34.84GB.
I conclude that I need at least 40GB, if not 50GB, to meet my data demands for 30 days.
But, I'm currently stuck on contract with Singtel, under the 15GB for $20, until January 2020.
So, not ideal for me to change plan now.
Whereas for minutes and SMS, today is day 17 out of 30 days of the current biling cycle (12 August to 11 September),
I only used 2 out of 150 minutes, and 0 out of 500 SMS. Which is consistent with my historical mobile phone usage all these while.
The only way to survive with such limited data, which is already better as last time I was using only 6.5GB for $45 (the Singtel "adjustable" plans), whereas now I am using 15GB for $20 (the Singtel Sim-only plans), is to taper my usage to only use WhatsApp.
Not against Singtel. Because other telcos are also like that.
Circles.life 20GB for $18 also not enough.
I need 40-50GB. Although now cheaper than last time already. But I still cannot afford.
(My LCP allowance only $766 per month. Not like the working adults, whose allowance is at least $2000 per month. But think about the recruits, only $560 per month. The telcos should really consider having NS plans, that provide lower prices for NSF during their 2 years of National Service, and also, comparable to today's SIM only plans.)