Cheaper to to stay on $25 plan if it is the same as the $55 in terms of amount of data, talk time and sms.
2 years = 24 months
Recontract with $55 per month and $87 upfront = $55 x 24 + $87 = $1407
Stay on $25 per month and $649 upfront = $25 x 24 + $649 = $1249
Difference is $158
if one has CIS promo especially for singtel. it will make a huge difference.
If i took 2016 iPhone SE singtel price plan as comparison.
Combo 3
16GB - $37 (equipvalent to 64GB for 2020 iPhone SE)
64GB - $187 (equipvalent to 128GB for 2020 iPhone SE)
Combo 3 usual price: $68.90
CIS Combo 3 price: $41.34
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if 2020 iPhone SE singtel price plan is similar.
Combo 3
Total cost of ownership over 2 years
64GB = $992.16 + $37 (upfront payment for phone) = $1029.16
Price paid for 2 years plan: $1029.16 - $649 = $380.16 = $15.84 for 2 years of service with 4GB data and unlimited talktime and SMS, free 24 mths' caller id and autoroam.
a lot of time there will be free sim card and registration fee worth of $48.15 or sometimes under promo they are also free for new/recontract.
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Combo 6 usual price: $95.90
CIS Combo 6 price: $57.54
Total cost of ownership over 2 years
64GB = $992.16 + $0 (upfront payment for phone) = $1380.96 - note: obviously it is more worth it to get 256GB for $102.90)
Price paid for 2 years plan: $1380.96 - $649 = $731.96 = $30.50 for 2 years of service with 7GB data and unlimited talktime and SMS, free 24 mths' caller id and autoroam.
Note: if you are on heavy data usage, subscribe the XO plans will be more worth it. You can more data even more than sim-only plan for similar price. This is just an example.