I know I am part of Apple's iPhone problem but even after doing all my research, I still don't feel the need to upgrade (AAPL)

iPhone 7-Plus

At the beginning of January, Apple announced that its holiday quarter revenue would be 7% lower than expected due to weakening iPhone sales.
Not having upgraded my 7 Plus for over two years, I know I am part of Apple's iPhone problem.
So, I made a trip to my local Apple Store and did some research to see if I should finally upgrade to an iPhone XR or XS. Here's what I decided.

I am part of Apple's iPhone problem.

You see, I own a perfectly fine iPhone 7 plus that I've had for over two years, and I feel no pressure to upgrade.

My screen isn't cracked. All the apps I need are running smoothly (despite the occasional crash). And I like to think that my photos still stand up to my friends' who shoot with their new, notch-laden iPhone XR and XS.

Bah humbug! I'm sticking with my 7!

I was curious, though, how much it would cost to upgrade and would that cost be justified?

The Face ID feature to open a locked screen seems nice (my thumbprint only works 50% of the time when it's sunny out and 0% when it's raining). And maybe having Portrait Mode on the front facing camera would help make me look less awkward in selfies. Maybe not.

Anyways, I headed to my local Apple store in San Francisco's Union Square to figure out if I should finally upgrade or not.

Here's what I found:

If I were to buy the cheapest of Apple's new phones — the 64 GB iPhone XR — my monthly fee would be $37.41 through its financing program.

That $37.41 is exactly what I was paying per month for my 7 Plus.

But since I haven't upgraded my phone for over two years, my monthly payments are no longer. Starting last September, I owned my phone outright and have been paying $0 to Apple since.

So, if I were to upgrade, I'd have to get used to a monthly payment again.

If I traded in my 7 Plus (which is in good condition), I would receive a $300 credit through Apple's GiveBack program.

That credit could be used for future monthly payments and paying taxes on my next phone.

Shoot! I always forget about the taxes. Let's figure that out real quick.

The 64 GB XR retails for $749, and the sales tax in San Francisco is 8.5%. So to walk out the door with my new XR, I would have to pay $63.67 in taxes.