It would help if you gave the make, caliber, and condition of the pistol when you asked this question. Without that it all guess work.
30-90 or so
From what I have read so far it was made by mossberg. This is based on some articles I found doing a basic google search of the firearm name and serial number.
I can't tell you what it worth but My catalogue says it's a Mossberg 500E made by Mossberg.
High Standard 1959
50-150 dollars