Notice on the site for the Diamond it States * Mail In Rebate Require an Everything Plan" So you do not have to change your plan unless you want the extra 100 off BUT is the 100 off for the phone honestly worth losing a plan that saves you 50.00 per month every month. AND if you have a special plan you are getting your employer discount say if you work for FORD motors you are getting a 25% discount BUT the Simply everything plan 99.99 you do not get a discount of any kind and discount are not stackable in any plan so you can not get 25 percent off from NVP and then get an extra say 5 percent off. NOT POSSIBLE.
The ONLY phone that requires a EVERYTHING PLAN , whether it be Simply, or TALK MESSAGE DATA 450, 900 or 1350 indiv. plans OR SHARE TMD plans is the INSTINCT.
I hope this helps.