I live like 5mins from a police station. You dont work 24x7 lol. You are not taking time off to go and sell a phone. Anyway you will have to go the Apple Store for IUP, that almost always takes more time meeting a buyer locally.
There's absolutely no way IUP takes more time than the process you describe. The time spent backing up, selling, restoring selectively to a backup, dealing with the inconvenience of being on a bridge device without all your stuff, etc. If it works, you do you - that's the freedom they give us with a bunch of different purchase options. But for me, the numbers play out just fine for the convenience of the program. You also don't need to step foot in an Apple Store at all. new device and return box show up at your doorstep on launch day.
Here in California if I were to pay outright this year:
iPhone X 256GB $1149
AC+ $199
Sales tax 9.75%
~$1479 out the door.
Apple Upgrade Program:
"Financed" $1348, payments of $56 per month over one year = $672 out the door.
I paid $0 via Apple Pay on preorder night and the tax never showed, so I'm not sure what happened there.
Not only that, but Apple will take the phone back, close the remainder of the loan, and hand me a brand new flagship phone next year on day one? And it'll let me in a little earlier to the preorders? And you're building credit? That does it for me.