DuplaPlant 24 vs. other supplements

	I am just wondering if anyone knows why the DuplaPlant 24 is so 
expensive when it contains the same nutrients as are found in a lot of 
trace element mixtures. It may very well be more concentrated but still 
does not seem to be worth the money. 
	I have been using a broad spectrum trace element mix (by Kent) and
a Discus trace elements (also by Kent) on a 2 day basis.  As far as I
know, just about every element that could possibly be used by any plant or
animal is found in one, or both, of these supplements.  However, I would
like to believe that Dupla has a reason for charging what they do. Any