Another question about the surrogacy in the financial department...?

Ive researched a few couples to be a surrogate for, but I Absolutely HATE when they ask what my "fees" are. Of course beside the medical and clothing expense, they want to know the fee for me just for being pregnant. and I HATE putting a price on a child. But at the same time, im a stay at home, we live paycheck to paycheck on my husbands income, which he has a very good job, but still. The money is a plus and NO i am NOT doing it for just the money by any means, i would do it Absolutely free if we were in a better financial place in our life. How do i go about discussing my "fees" without seeming like a money hungry selfish "you know what"? btw, thanks for all the other answers to my other question about this.