It could be argued that the quality of a coupling cap has even more effect on the sound/transparency of a component than cabling and other rather expensive "tweaks". We all know how much some people are willing to spend on cabling and other esoteric tweaks... Once this is considered, the cost/benefit ratio is actually quite reasonable for upgraded caps, IMHO.
That said, these caps aren't for everybody- only those who are seeking the ultimate in performance out of their componets and are willing to pay the $$ for that gain.
Best,
Chris