Sands closed in '97, succeeded by the Grand and
currently the Inter-Continental. I value it at $15.

The El San Juan chip looks like an error chip if it has a blue edge. Al Rollins values it at $100
if it is the error chip. Probably could get $30 - $40 from a knowledgable PR collector.
Order my book on obsolete PR chips, $30 plus $3.50 S&H.