Since one male can breed up to five or more females, I need at least 5 times as many more females than males. To me, that makes the females that I produce at least 5 times more valuable than a male ... especially if I already own a male co-dom that produced the clutch.
Price is driven by both supply and demand ... because breeders are hanging on to females (in some case by an order of 5 to 1) the supply of females is much lower compared to males ... that's what makes females more expensive.
Hope this helps.
-adam