[colonelpopcorn]

Sexual selection certainly does. Eggs being expensive and sperm being cheap kind of make winners necessary.

[Thorrez]

The vast majority of people aren't buying or selling eggs and sperm. So I doubt the price of eggs and sperm are creating an economic divide.

[tenebrisalietum]

It is possible for the words "Expensive" and "cheap" to mean or refer to actions other than buying or selling.