If you don't need to play games then you can upgrade every 6 - 10 years these days. I am still using a core 2 duo 3Ghz, geforce GTS250 computer at home and it plays 1080p flawlessly using windows 10 using with Showmax(720p) and Kodi(1080p). Just give the computer plenty of RAM when it's new and cheap. These days 16 - 32GB then it will last years and years.
I'm still rocking a 2011 2600k, and I play games. It's probably getting to the point where I should think about upgrading.