How much does it cost to downgrade an iPhone 6 plus to and iPhone 6?

Your best bet it to sell the 6 plus and use the proceeds to help pay for the new 6. Depending on where you bought the phone, there may be a trade in program, but what you get for the current one will be limited.

Depends how you got the phone. On contract, the new rent to own program, or bought outright. Using someones eligibility used to be the way to go, but you'd still have the old phone to deal with. If you bought it full price you might get 75-80 % of the original value. The longer you wait though the less you're going to get for it. And make sure you log out of all your iCloud accounts before selling it. Don't sell a brick to someone.

Before doing anything, talk to your carrier and make sure you understand fully any implications of canceling a contract, using someone else's eligibility, what you'll need to pay for the new one, whether or not you get to keep your number, how it affects any other phones on the account, etc. It's best to go in with full knowledge rather than having something happen after selling your device to a stranger and can't get it back.

I agree with anypats. Talk to your carrier, because they'll have a clearer idea of what your options are in regards to all the issues stated above. We don't have access to your account so we can't really answer your question. If you do decide to sell it and have questions on how to prepare the phone to sell to someone else, that we can help with. And if for some reason you decide to buy a phone from another person and not through a retailer, make sure you take a Sim card, activated or not, and setup the phone the entire way to the main screen. It takes a couple screens and a Sim card to get to the activation lock. A lot of people buy phones "off the street" and don't take the time to do this and then realize when they get home that the "new" phone they just bought is bricked to someone else's iCloud account. In most cases, its a stolen phone.

Contact your wireless carrier, or use Apple's recycling program if applicable, or sell the iPhone 6 Plus to someone other than Apple or your carrier.

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