With a couple hours of work, it’s pretty simple to pull the power supply from an old PC relic and turn it into a pretty decent bench system for powering your electronics projects. The standard ATX power supplys that you find in desktop computers have regulated 5 and 12 and 3.3 Volt outputs with sufficient power for most small project needs. You probably have a few of these just collecting dust in the basement, which means you could have a test bench PSU for quite a bit less than the 80 bucks you’d drop for one on

WikiHow and Instructables both have a decent howto on the subject. As always, be careful when working with high voltage electronics. Nobody wants “almost saved $80” on their epitaph, so mind those capacitors.

Convert a Computer ATX Power Supply to a Lab Power Supply
ATX -> Lab Bench Power Supply Conversion