Trade secrets are one thing, but the chemistry of the blend you are using is another. If you use more of the blend than the polyurea, then legally you can not call it polyurea. I beleive the percentage was stated as 15-85. So you see, the chemistry of your blend does make a difference. And you did bring your "solution" to the table for discussion.
So lets discuss.
First you are claiming a cost of $3.65 a foot for your product, complete with the underlayment. At the stated website prices, you might get close to that, without shipping and the underlayment.
Just for product and shipping it is $4.15 a foot. Then you need underlayment. Then you also need to either purchase or rent the gun to put the materiel down with. That will add at best 30-90 cents a SF depending on the size of the pond you are applying the materiel to. Then add the proper safety equipment, and you are in the 5-6 dollar range. And that is at the 50 mil thickness.
So either your pricing is wrong on your website, or your claims that you can do it for about $3.65 a SF complete with underlayment, is much less than honest.