As I mentioned a couple of posts ago, I've owned each of the iPhones. The original I bought December of '07 because that's when the finally arrived in Alaska (December 9th, a Sunday---I remember it fondly

). The original was 'un'subsidized. I believe 399/499 for either 4 or 8GB of storage. (Maybe it was 2/4---doesn't matter though). This was the ONLY one that I lost money on. About 20%. I sold them for 300 and 375 respectively when the iPhone 3 released. My wife and I run a small audio and video production company with about a dozen full time employees. Each we provide phones (iPhones) too and take care of their plans. This has allowed me the ability to upgrade each year without penalty from my carrier (instead of waiting the two years typical). As a fella fond of the iPhone, I've taken that advantage.
Since the sale of the original, I've always either broken 'even' or even made a bit of cash on the sale of the previous generation phone. Obviously, I'm signing a new '2' year contract...but I'm very happy with my carrier and will always need a cell phone. I'm not concerned with the overall long term price I pay...as it's similar to other 'smart phone' choices on the market (Plan-Wise). However...the difference being, the iPhone DOES hold that initial purchase price value, compared to most other hand sets on the market. This past year, I sold my 32GB iPhone 4 that I had owned for 18 months (since launch) for 375...a $76 profit. For $24, upgraded to the 64GB 4s.
That all said, (sorry, had NO intention of rambling that long)---I do NOT buy a phone nor look at it as an investment. It's a phone, but I'm almost 41 years old. My original phone was HUGE!!! Back in the early 90's I remember each upgrade I did seemed to be revolutionary

The battery length was a biggie...cameras, even going from the monochrome to color screens...Texting with the 10 keys, etc, etc. However...I NEVER upgraded, nor did I look forward to upgrading until the phone I owned was ready to be laid to rest. At that point, I always upgraded to whatever the "Free" phone of the month was from my carrier. Could've cared less whether or not it was Motorola, Samsung, LG...I didn't care.
The iPhone dropped and absolutely BLEW up the world of cell phones in my little world. With what my wife and I do (and have for the better part of two and a half decades), it was an absolute God-Send! Each new phone has become quicker, with better cameras and application access, the eco-system (apps available to our business)...all the way around, marked improvement. The same can be said for US with the iPad. I've been amazed how well they hold their value as well.
I came from the PC/Windows/Who gives a S4!t cell world about 6 years ago now, all with the purchase for my wife of a MacBook in 2006. It's completely changed everything about my life and business...and I've been delighted that I can actually sell an older, used--but well taken care of piece of gear (whether it me an iMac, MBP, iPhone...doesn't matter) from Apple and come out with some money on the backend. This was NEVER the case with a used PC or generic cell phone (of course, the cells were 'free' to begin with and back then I would Never DREAM of actually putting out money for a cell phone on contract

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Again...sorry to babble, but while the iOS devices should NOT be looked at as a financial investment....they indeed DO hold their monetary value well! As far as their intrinsic value/investment...IMHO, they've been invaluable assets to have! It's just a little bonus to recoup on the backend
J