If you would like to build your very own benchtop power supply you might be interested in a DIY tutorial for Supplino. A versatile compact Arduino power supply capable of providing from 4 to 40 ...

Another answer is to find a higher voltage supply and mate it with a cheap power supply module. We’ve also seen non-PC power supplies put in a PC case.

The Pico is a "low-cost breakout board" that is designed for the use of RP2040, provided that it has 2MB of flash memory and a power supply chip with an input voltage rating of 1.8. to 5.5 volts.