I skimped out and bought a $20 multimeter - it's now one of my best toolkit investments

This article reviews the Neoteck TS20D 3-in-1 pen-type multimeter (~$25), highlighting its 6,000-count resolution; AC/DC voltage, resistance, diode, capacitance, non-contact voltage, temperature, frequency, and phase identification features; CAT II 600V safety rating; large LCD; LED work light; included probes/clips/pouch; and AAA battery power. It notes the lack of amperage measurement, cites listed accuracy (±1% AC, ±0.8% DC), and concludes it is an accurate, durable, and affordable alternative to pricier options like the Pokit Pro for most DIY tasks.