A full dealer service on a 15 year old car is a nice to have but will not net you any gain if the overall car is worn or tired
If its mint when you come to sell it it might help get you a few more quid on high miles but not a fraction of what it will cost you to take it to VW.
If you can afford it by all means for piece of mind, but I would pay half the cost and take it to a specialist 
Learn to type English, and then take it to a VW Specialist
Don't knock the Scott's we would be worse off without them, if I typed how we speak in London it would sound truly ridiculous
I am Scottish - Born & Bred.. Still no excuse for typing total rubbish....
As for full dealer history... I wouldn't dream of taking my Mk2 to the dealers... Do you really think that a young Mechanic who works for VW is actually trained on how to fix a car that older than him... NO CHANCE...
Take it to an appointed VW specialist and save a few quid & get proper service with people who know what they are doing...
His is a 4 year old golf, so your point although valid for a Mk2 even though its simpler is not relevant to him.
It is still new enough to be covered by a warranty plan at VW which although expensive covers you with convenience.
I wouldnt take it out but then I'm a have ago hero and tight to go with it.
The same type of warranties can be bought at VW specialists for less but do not come with main dealer cover.
This is the lesser of two evils imo and would be what I would do if I had to, but his question was about if it was worth it in terms of payback when selling in 11 years time.
And my answer was no not really.
Selling it next summer, then definitely yes for either option.
I know his post is not strictly the Queens English but when did this forum become GrammarNazi.co.uk.....
Give him a break