You can see on ebay the average value .... and sometimes the prices are higher because of the Ebay fees and Paypal fee .. and sometimes the shipping fees are absurd.
For an Example:
I will have a 34401a for sell in not too long , no fresh calibration, had all the capacitors changed in it ...
I would expect maybe 400$ cad for it ?? once the combined fees removed ??
Or a direct sale outside Ebay.
Some used models are selling way too high, some of them have unobtanium parts ... dim VFD's etc .... you have to know what you're buying ....
And i've seen a tendency like " the more you talk of it / them on a forum the higher the price goes loll "
The famous Fluke 189 is selling at minimum / around 200$ usd and goes high / up as 300$ usd
?
Paid a fortune for Gossen Metrawatt meters, way too high, but they almost can't be found on North America continent.
The only thing i may add : do a search for services manuals / parts availability .... here on EEvblog some of them are very popular, but the parts ...
Popular models ...
Hp 3468
Hp 3478
Hp 34401a
Keithley 2000 series, some 195 196 models too
Solartron
Datron
Hp 8xxx series
Phillips / Fluke meter
and the list goes on and on
You have some great repo's / web sites for finding users and services manuals
EditAND Finally :
Check for the calibration prices of the meter you want, you may get a surprise, here in Canada / Quebec city a 34401a will cost 150$ cad to be calibrated and certified .. a Fluke 189 is 75$ cad ... they go by the meter display counts loll