On Fri, 9 Sep 2011 12:49:26 -0700 (PDT), Frank Foder
wrote:

One would think that as the concentration gets lower the price would
go down. Nope. Price hasn't changed. The water they use to dilute it
must be pretty pricey stuff! In a few months they'll be selling
vinegar for $7/gallon.

You're paying for packaging and shipping. They throw in the acid for nothing.