Price? 1732 Silver Pillar Dollar (Piece of Eight)

I'm needing some more information about this coin. It came into my possesion about 5-10 years ago through my family.

The front side says "VTRAQUE VNUM" and has a mint mark of M with an O above it. Also dated 1732. Front has a picture of 2 globe looking objects with a crown on top and 2 colums on each side with smaller crowns on them.
The backside is different than any other Silver Pillar Dollar I can find on the net. It simply says "SILVER PILLAR DOLLAR (PIECE OF EIGHT)" and "PIASTRE AUX COLONNES D'HERCULE (PESO)" and a few flower/leaf/ribbon imprints on it.

I'm not much into coins so I can't really tell what the grade is and would hate to guess. It is worn/circulated and the silver is now very tarnished and black(has been since I recieved it). I'm basically just curious about some of the history on this coin and a price hopefully . I just want to know if it's something I should put in my safety deposit box instead of sitting around the house in aimless spots and/or insure. I can take pics/scans if they are needed.