I think it is best to anticipate what to do with a old equipments when you purchase them. By adding a few percent to the price, you can extend the afterlife of hardware by several years.

For example, I built a desktop in 2004 with space for additional RAM, low power mother board with integrated graphic chipset and SATA capable:
1) An additional powerful graphic card allowed my little brothers to play until the left to University (3 years);
2) With more RAM, my mum could still use office software (4 more years);
3) Without the energy hungry graphic card and with big SATA drives (originally with PATA because of availability and price) it is now a happy file server (2 years and still running).