|Samsung S7 on SingTelShop Online|
The answer to the question usually depends on the phone in question. If you are getting a decent phone, then it is probably a good enough deal since you don't pay a cent apart from the monthly subscription.
Though in this relatively bad economy climate, there is a part 2 to the question.
|Calculations with prices as of end January 2017|
Row 8 to 13 is similar to row 2 to 5 except that in column C it shows the approximate prices that you can resell the corresponding iPhone for.
I think the chart is pretty self-explanatory. Essentially you do a bit of homework and understand which phone offers the highest amount of rebate. And if you would like a budget phone, you are more likely to be better off with recontracting an iPhone, sell it and buy phone of your choice from non-telco shops.
In this example, you can also try to recontract a Samsung S7 due to it's higher savings against the retail price. But that retail price is what you can buy the Samsung S7 for and if you try to sell a brand new set outside after recontracting, you certainly get a much lower amount. iPhone has a reputation for better resale prices and take-ins.
I want to point out the retails prices are quoted from the trusty Kaisa Mobile and Mobilehardware Zone. They offer good prices and genuine Singapore sets.
Link - Kaisa Mobile
Link - Mobilehardware.