The life cycle of a computer
1995 - Bought our first PC from Time Computers. It cost around £1000 and had about 4mb of storage (or something unreasonably small)
1998ish - Computers had moved on at such a pace that new software wasn't compatible and we were running out of storage. Decided to start again and buy a new computer, costing about £1200. Decided to go for the best spec we could afford, so that it would last longer than three years. Think it was a Tiny computer.
2000ish - How can computer technology move so fast?!! High spec Tiny is now virtually obsolete. Need to start again. Bought a Dell PC. Fortunately, prices are beginning to come down, so got a reasonable spec for £900. New PC also promises to be upgradable, so ending this cycle of buying a new one every three years.
2002ish - PC getting a bit sluggish and laptops are now popular. Cleaned up the Dell a bit, did some maintenance to keep it running but bought a laptop to go alongside it. Cost about £1000.
2004 - Got a new job and a high spec Dell laptop as a perk of the job. Best laptop I've ever had! Fortunate really, as the Dell PC, which was upgradable, is now not so upgradable. Nobody could have predicted how quickly things would change.
2008 - 2012 - Acquired various laptops, netbooks, tablets and smart phones. Cost variable.
2013 - Having returned from Finland, needing a desktop PC that could cope with some high-intensity software, decided to build our own computer. Josh (then 18) and I chose parts, ordered them from Amazon, and built a PC. Much to our amazement it worked. Cost £477.85. Should be upgradable but if not, at least it didn't cost as much as normal!
2014 - Computer still working as though it was only built yesterday.
2015 - Yep, still going strong.
2018 - This is the longest I have ever owned a computer and not needed to replace it. Haven't even upgraded it yet.
2019 - Changed career and now need higher intensity graphic software. For the first time in 6 years, feel that some upgrades might be good. Thinking about it, as Josh recommends upgrading most parts. On the plus side, he has a good graphics card that he'll hand down. Predicted cost - about £490. That is more than the original computer but the final product would cost £1330 to buy off the shelf. It should then run all the Adobe stuff and all the eLearning authoring tools that I use, as well as being a bit faster.
It's funny, when laptops came out... and then tablets, they predicted that desktop computers would eventually become obsolete. Okay, so I still have a work laptop and a Chromebook for just sitting on the sofa and browsing the net... and of course, I have a smart phone... but what I use most, is my desktop PC. I work on it, play on it, learn on it. It is anything but obsolete.
My advice, if you've got the technical skills (or a cool son or two with such skills) - never buy another PC off the shelf again. Order the parts and build your own. It's cheaper, more tailored to your needs and would appear to be genuinely upgradable.