I believe i am Scottish so i'll give it a go
To me 'Highlands' ONLY means Scottish Highlands, almost anyone who hears the word Highlands thinks of Scottish scenes straight away.
It is a strong keyword with very obvious development potential and a large number of potential end user with there being such a strong tourist industry in The Highlands and cause Scotland has a strong history of using the Internet well to promote their areas.
Price wise I'm not as optimistic as Len, I'd guess it's worth low - mind $xxx right now though you could get more if you hold.
I checked the past domain sales with 'Highland or Highlands' in the title and found very little:
highlandgames.eu sold for $333 , 2007-01-17 @ Sedo
highlandschool.com sold for $560 2006-12-11 @ TDNAM
Good Luck with it,
Ronnie
