We are not even factoring the resale value after a couple years, of an iMac vs a generic hackintosh.
About time - I suspect more than a handful of people will find spending a day here and there worthwhile if it saves them $400 + $169. (Also if in best case Apple keeps your iMac for 2-3 days in repair - that's time lost as well. You could do the Hackintosh repair faster yourself.)
The OS upgrades however - yeah they will be a pain. I can see that as a significant deterrent.
I can sell a $3000 iMac for $2000 two years down the track; making the upgrade "cost" $1000. It'd cost me roughly the same to buy a GTX 770 (AUD$500), a new i7 Haswell and a 128GB SSD, which are effectively the major upgrades between my 2011 iMac and the (predicted specifications) of the 2013 refresh. And then I have to hope that someone else has tested those parts before I have!
The Mac Pros are the only Macs in recent memory that I've kept in service for 5+ years, with multiple rounds of disk upgrades (boot SSD + 3TB, then 6TB, currently 12TB), and graphics card and RAM upgrades as well.
If that's important to you, you currently either need a Mac Pro or a hackintosh.
Of course, once the new trash-can Mac Pro ships, there won't be any Macs from Apple like that anymore...
Yes, it is slow compared to the newer machines, but it has lasted a hell of a long time!
You sir, win that award.
Kind of off topic, But in Australia the AppleCare is kind of a moot point as consumer protection laws mean Apple provides free repairs, replacements or refunds for something like two years.
From what I've heard it's similar in EU and China (and I believe Mexico, but I'm not sure where I've heard that from).
No, good point actually! (I was commenting on OP's speculation that a hackintosh might make more sense in the US)
Not only does it make financial sense - the upgrade-ability and repairability of a custom build in unparalleled by the iMac - esp. the newer one. You would at least need the $169 AppleCare to allow for the possibility of free repairs on the iMac for 3 years. That still leaves out upgrades. Whereas for the custom build it's just a matter of yanking out the failed part and putting in a new one at cost.