This is an interesting discussion to see on Macrumors, of all places.
As I recall, I dropped about $1300 for my first Mac out the door(including Applecare), and it was-at the time and still-one of the lowest end laptop that Apple made(13" Macbook Pro). It just turned three years old a few months ago, and honestly it's still completely useable and I don't see that changing anytime soon. Now that it's out of warranty, I'm planning to stick in a good SSD(probably a 1TB Samsung Evo) and maybe do the Bluetooth LE mod to enable handoff with my iPhone 6. I think I can easily get another three years out of it at a minimum, but it was still a relatively expensive purchase for what is effectively a disposable product. User upgradeable options are much more difficult on newer Apple latops.
Admittedly, I spent last week primarily using a last generation 15" Powerbook G4 that's now approaching 10 years old along with a G4 Quicksilver now approaching 13 years old. This was done for a challenge in the PPC forum, and admittedly I didn't find myself too cramped but still gave up a lot of useability over a newer computer. If I'd still been working on my thesis, however, it would have been pretty much out of the question. Going a little bit further back to the late '90s, my PowerMacintosh 9600 is really only good for playing games and running software from the mid to late 90s(and it's been upgraded pretty heavily).
By contrast, my Rolex is 30 years old and will likely easily last another 30 with a little bit of care. I've spent lots of money on 100+ year old watches that continue to function just as they were made to do. In fact, in some ways modern technology can allow me to make such watches run better than new. The biggest advantages is with electronic timing machines(using a quartz oscillator for the time base) that can give instantaneous rate information in any position. This just wasn't possible 100 years ago-watch adjusting was done by measuring the rate over a couple of days. A timing machine gives immediate feedback about whether or not an adjustment was successful. Someone who has studied how to read timing machine traces can diagnose faults in the balance staff, balance jewels, escapement, and even further up the train in just a few minutes.
Yes, a good watch may be expensive, but when you consider that with proper care it can likely do the same thing for your grandchildren as it does for you it's not so expensive.
Again, an excellent and well argued post.
Anyway, I agree with you about the longevity of a beautifully made and exceptionally well crafted watch when contrasted with a piece of equipment such as a computer, or, above all, for that matter, the Apple Watch.
I upgrade my computer every two to three years, but, I don't have a car, and I see it as a vitally necessary tool to enable me to carry out my work properly.