Summary

This is my poor man's dual lab power supply.
Component list:
Display: https://www.aliexpress.com/item/DC-0-30V-10A-Voltmeter-Ammeter-Blue-Red-LED-Panel-Amp-Digital-Volt-Gauge-meter/32597785507.html
DC Converter: https://www.aliexpress.com/item/1pcs-DC-1PCS-DC-Step-Down-Converter-Module-LM2596-DC-4-0-40-to-1-3/32758699224.html
This is to replace the onboard potentiometer on the DC converter: https://www.aliexpress.com/item/5pcs-10K-OHM-3-Terminal-Linear-Taper-Rotary-Volume-B-Type-Potentiometer-Pot-New-Arrival-High/32701017712.html
Terminals: https://www.aliexpress.com/item/2017-New-Hot-5-Pcs-2-Positions-Connector-Terminal-Push-in-Jack-Spring-Load-Audio-Speaker/32802688094.html
Power IN Jack: https://www.aliexpress.com/item/2-1mm-x-5-5mm-Power-Male-Plug-Female-Socket-Panel-Mount-Jack-Plug-FOR-DC/32782915239.html
and of course some DC power adapter: https://www.aliexpress.com/item/EU-US-AU-UK-Plug-110-220v-AC-To-DC-12V-15V-16V-18V-19V-20V/32615281462.html
Input: 4-30V, Dual output 1.25-30V, 3A max.
Cost: minuscule :-)