Source: iMore
Best answer: Apple doesn't sell the iPhone 7 anymore, and although you may be able to find one used or through a carrier, it's not worth buying right now. If you're looking for a cheap phone, the iPhone SE is sold by Apple, and it's very similar to the iPhone 7, but features much better speed and performance.
Why do you want the iPhone 7?
I know it can be tempting to buy an older iPhone from a carrier offering a deal, or a mildly used one for way cheaper, but as a general rule, purchasing used iPhones aren't my first choice. They can be a bit of a pain to properly transfer ownership due to Apple's strict software that locks iPhones to certain iCloud accounts unless you deactivate them properly. Plus, even if the phone looks fine on the outside, it could have battery problems or problems with the internals that you might not notice before purchase. Buying a new iPhone is always a safer investment.
Of course, maybe you're looking for an iPhone 7 because you don't like how big and bulky iPhones are these days, or you really love TouchID and don't want to lose it, the goods news is the iPhone 8 can help with all of that.
The iPhone SE is just better
The iPhone SE has everything the iPhone 7 does. It's water-resistant, has TouchID, is the same form factor and size, and Apple sells it, meaning it readily available straight from the source.
The A13 Bionic chip packs enough power to get you through anything you can throw at the iPhone SE, from gaming for hours on end, to lots of emails, texts, Facebook messages, tweets, and every other type of communication. Plus, the UI and new features of iOS 14, like widgets, run amazingly well on the iPhone SE.
There's no denying that opting for an iPhone that has Apple's old design has a few drawbacks when you compare it to the iPhone 11. You're not getting an OLED display, the TrueDepth selfie camera, or the near bezel-less design, but in honor of saving $300, the iPhone SE still has a lot to offer.
iPhone XR has the new form factor for the lowest price
The iPhone XR features quite a few upgrades over the iPhone 8, including the new design, even bigger display, Face ID, and dual-SIM support, but still has some of the same features like wireless charging, and LCD screen, and a single rear-facing camera. Of course, the iPhone XR is bigger than the iPhone 8, and if you're a fan of small phones, the iPhone XR will likely fail you in that regard.
The iPhone XR is a great option for those who don't mind spending a little more to get a more updated and modern looking device.
The iPhone 11 is the most future proof
When buying a slightly older model of a phone, it's natural to be worried about how well (and how long) the device will still be running as newer models come out. The good news is Apple has an impressive track record when it comes to supporting older devices with new software updates; however, iPhones do get phased out.
Most likely, the iPhone 8 would be supported for a year or two, but beyond that, its anyone's guess to how long new iOS updates would make their way to that older hardware. If you're looking for a phone that will last you as long as possible, the iPhone 11 is the cheapest new model of the iPhone.
No, you don't save a ton of money when you buy an iPhone 11, but it's a reasonable size (though not as small as the iPhone 8), and it will ensure you will have it supported for years to come.
Best inexpensive iPhone

iPhone SE
Just like the iPhone 7 but much much better.
While it may lack the new design of Apple's newest iPhone, the iPhone SE still offers an all-glass design that allows for wireless charging, has an IP67 rating. Plus, it has the A13 Bionic chip, the same brain that powers the iPhone 11 models.
Cheapest with Face ID

iPhone XR
Face ID, TrueDepth selfie camera, and minimal bezel design.
If you're looking for that new design look that offers an edge-to-edge display, Face ID, and the TrueDepth front-facing camera that allows you to take portrait mode selfies, the iPhone XR is the cheapest way to do it.
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