Era
Gear from the 2010s looks and works like a current product, with color screens, USB and LAN as standard and GPIB often an option. Many features are software licenses tied to the serial number, so any option a listing claims should show on the instrument's own options or about screen. These units are recent enough that the maker often still supports them, which makes calibration and firmware updates easier to get. Check the screen, the buttons and the input terminals for wear.
2 models we cover.
HP / Agilent / Keysight
Multimeter$1,275–$1,625 typical ask
148 on eBay
Keithley
SourceMeter$6,125–$7,675 typical ask
83 on eBay