How concerned should I be about getting a used Meter?
Like buying anything used you should consider the following.
1) Has it been used or abused?
Some meters are abused (subjected to way too much current, energy, voltage, etc). The input protection components on the pcb may be bad, but won't be obviously blown.
2) No warranty from manufacturer.
Fluke will not honor any warranty on used meters. (* note n1 *)
3) Check its condition.
Assume the meter has been dropped. Check for cracks, broken plastic pieces (inside and out), etc.
4) Verify everything is working.
Test every function. For fuses, take them out of the meter and verify they are the proper HRC size and rating. I bought an used Fluke 87 locally and I tested the fuse as per manual. It wasn't until I got home that I found out my HRC fuse was a steel threaded bolt (* note n2 *).
A member here sent me a real blown 440mA Bussmann fuse, but patched with a thin wire. He told me so and used it just for testing purposes. Thinking about this, I could easily take any blown fuse, solder a thin wire, turn it so the wire is on the bottom where you can't see the wire and try to sell this as working fuse inside a multimeter.
5) Check to see if it is stolen.
Flukes are very popular in the USA. With its eaisly spottable yellow holster, they sometimes grow legs and walk. The serial number should be on the back of the unit.
*notes*
n1) Fluke has issued a number of recalls on their handheld meters for safety reasons. They seem to be very generous if you call in and tell them you have a meter with a known safety issue and they will likely repair/replace your meter for free. See
https://www.eevblog.com/forum/repair/multimeter-repair-time-again!-fluke-177-reads-8-ohms/n2) See
https://www.eevblog.com/forum/chat/buying-used-multimeter-what-to-watch-for/