That's an older version of the 18, the new 18 looks a bit chintzy to me. Yours I'd guess it's 90's? The value of yours is likely in that - if you can find a year of bottling then it's the kind of thing people buy for people born in that year. It won't be a fortune, but yes it'll be more than the standard Glenmorangie (a very fine drop regardless) but might not be more than the current 18. It all depends on the year and the condition. Could contact one of the whisky auction houses to see.