...and if you've bought a PC Download game from Amazon.com in the last month, you got a $5 credit coupon for use against any Editor's Choice game during January, and we know that Dark Souls is one of those games. It's probably gonna be $18 then, so it'll be $13 if you have the coupon and a little patience.
Of course, if none of that applies, then by all means go for it.
I thought you couldn't order DD content from amazon.com if you're outside the US?