There has been a lot published about why potential Apple (NASDAQ:AAPL) iPhone customers should skip out on the iPhone 8 and iPhone 8 Plus and go for the now-discounted iPhone 7 series phones instead.

Business Insider's Dave Smith, for example, recently published seven reasons that customers should skip both the iPhone 8 and the iPhone X and instead go for the iPhone 7. The key argument that I've seen from those who advocate buying the iPhone 7 instead of the iPhone 8 is that the phones are similar but the iPhone 7 is cheaper, so the latter is a better deal.

Apple's iPhone 8 Plus on the left and iPhone 8 on the right.

Image source: Apple.

Here's why you should think twice about following this advice.

Don't ignore the storage differences

The base model of the iPhone 7 with 32GB of storage now sells for $549 -- $100 less than it did at launch. The base model of the iPhone 8 with 64GB, on the other hand, sells for $699 -- a $150 premium.

Now, a $150 up-front difference isn't a small amount of money, but it's more than worth it.

First, the base model of the iPhone 7 has just 32GB of storage; many smartphone users will quickly fill that up and could be forced to constantly delete pictures, videos, and apps whenever they want to take new photos and videos, or download new apps.

The iPhone 8's base storage of 64GB, on the other hand, should be a much more comfortable amount of storage for most buyers. 64GB is enough to hold quite a lot of apps, pictures, and even videos.

Now, one could conceivably make the argument that it'd be a better use of money to opt for the 128GB iPhone 7 for $649 instead of the 64GB iPhone 8 for $699, but Apple added so much value elsewhere that the argument doesn't end here. 

Higher cost but much greater value

Let's suppose that a value-conscious buyer doesn't care about some of the features that Apple introduced in the iPhone 8, like the glass back (this is mainly an aesthetic change), wireless charging capability (wireless charging requires expensive accessories and it's not that great anyway), fast charging, or even the True Tone display.

I still think that the iPhone 8 is a better value than the iPhone 7 for such buyers.

For one thing, the camera in the iPhone 8 is dramatically improved from the one found in the iPhone 7, with significant improvements to both still-image capture and video. Considering that smartphones serve as many people's primary, if not only, cameras, it's probably not hard to justify spending a little more to dramatically improve the quality of the photos and videos that one will take over the course of two to three years.

Beyond camera quality, the iPhone 8's A11 Bionic chip is substantially faster than the iPhone 7's A10 Fusion. Apple claims an improvement of 25% in CPU tasks and 30% in graphics tasks over its predecessor.

While it might be tempting to make the argument that the A10 Fusion is "fast enough," the reality is that as phone hardware advances, apps become more complex and demand more processing power. The faster chip not only means an arguably smoother user experience today, but it'll mean that the iPhone 8 will manage to stay snappy for longer than the iPhone 7 will.

From a long-term cost perspective, if buying the iPhone 8 today means that you won't have to upgrade your phone for another three years, versus having to upgrade in just two years if you buy the iPhone 7, then the iPhone 8 will ultimately deliver a better value because it lasted 50% longer for just a 28% increase in price.

This is the point that a lot of the folks recommending that you buy an iPhone 7 over the iPhone 8 ultimately miss: $150 extra gets you a better phone that has the potential to deliver a better user experience for longer. For buyers looking to get the best value, the iPhone 8 seems like a no-brainer pick over the iPhone 7.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.