I'm in the uk and I've stuck with my older device simply because the 7 wasn't appealing enough to me. While calculating the cost have you compared with a sim only contract for a year? I'll certainly recommend that.
If that is the case, I'd think hard about re-upping next year instead of this year.
But what does it mean re:rates if you are not 'signed up' right now?
My pay monthly contract just rolls o,n the data and minutes are good for me. I get 5gb data and unlimited text and mins. If I switch to 20gb get the 256gb 7 then over 12 months I pay out less, providing I sell my 6s for 300 pounds or more. This tariff also allows a new handset in 12 months.
As before thanks for the comments all.
Regards
Josh