The value of ANY firearm is based on exact make, model and condition. You gave us one of the three items we need to answer.
350$ to 420$
50-300 USD or so
100-400 USD or so
$250-$375
Taurus made several 9mm handguns. Which model did you have in mind?
100-260 or so
There's no such thing as a 9mm Desert Eagle.
50-100 USD
No
Maybe a Taurus....
50-75
40-400 usd