You still spend £527.97 over 18months if it's 15@£35 + 3@£0.99
Seems mental that people pay so much on pay monthly contracts

and they pull people in by offering a free
£130 (in pcw) monitor.
Not sure if you can change after so many months, but then your still on a 18month contract
You could take off what the phone would cost you aswell I guess (
£100 unlocked), but it's still a lot of money.