More expensive data plans for current customers than for new

[EL20]

Why is it more expensive to change my data plan to 10gb as a current customer than it is to just buy a new phone and add the data plan on? When I try to buy a new phone 10gb of data is £10 a month but if I try to change my data plan for my current contract it is £12 a month for 10gb of data, why? If I am already a loyal customer surely it should be cheaper? Would I be better off buying a new phone rather than upgrading? The worst part is I already pay more than £12 a month for less gb...

[caesarome]

The £10 price is to attract new customers so you could either buy a new sim (and have a new number) or call Sky to see if they will apply the £10 price to your current sim.