Elagabalus wrote:If you can afford it, it is never a waste to throw extra cash in, for a scotch aged an extra say 6 years.
I'd certainly disagree with the
never in this statement (statements containing an absolute are
never true

) though for the most part for those extra few years and extra few pounds you will get a better malt.
Whether it is
worth those extra pounds though is multifactorial. Certainly a lot depends on how much that money means to you as Mr T points out.
A lot also depends on your personal palate. 1) It doesn't matter a jot if the older expression is "better". Complexity is important but if the flavours and aromas you get from the older expression are less pleasant to you as an individual than those of the younger whisky then it is worth no more money to you. 2) It also depends on the sophistication of your palate. If you are educated/practiced enough to appreciate the finer nuances of the older expression over the younger then it is worth the cash (if you have it). It will also vary for different distilleries. Some people would much prefer a 15yo Laphraoig over the 10yo but not a 15yo Glenfiddich over the 12yo wheras the next guy/gal would think the complete opposite.
Of course it also depends on how much extra money it is. Take a Bruichladdich 10yo at less than £30 and upgrade it to a 15yo at £45 and you will (in opinion of my palate) have spent your extra money wisely. On the converse take an Ardbeg 10 and upgrade it to a 17 at the moment and will have had to pay silly money to have done it because rarity comes into it more than quality.
If you could measure the ratio between quality and price as a surrogate of value for money you would find that value will almost inevitably diminish as the whisky ages. Take Bruichladdich again:
10 £25
12 £28
15 £45
20 £70
40 £1000
The 15 year old may be a good 50% better than the 10 and just about worth the extra, the 20 year old would have to be nearly three times as good to be the equivalent value to the 10 and the 40 year old would have to be 40 times as good. If you look at Michael Jackson's scores for Ardbeg the scores do, for the most part, climb as the whisky ages but only by a point at a time. The cost certainly doesn't go up in such small increments.
I'm sure I had thought of another point when I started typing this. But it seems to have escaped me.

(Everyone sighs with relief...

)