Re: Balvenie 21 Portwood
$100! The cheapest I've seen it in the UK is around £65, so that's not a bad price at all.
As to whether it's worth the extra depends on your tastes. I certainly much prefer the 21PW's nose, which is more robust, chocolaty and slightly drier than the DW's, with the latter being fruitier but slightly thin in comparison. On the palate, the PW is again more robust than the DW and possibly slightly peaty, but the DW just seems to be the more drinkable of the two. Anyway, for $100 I'd definitely suggest picking one up - I know I would!
However, the 17yo Sherryoak beats them both hands down for me...