I could never eat a supermarket egg - from caged hens or even free range, after having eggs from our own hens. And being involved in battery hen rescues and seeing those battery hens, well, no way could I eat eggs from the shops again!!
I would say most of the eggs I sell from the gate are fertile as I have numerous cockerels - in fact, some people when buying them have asked if they would be fertile, so obviously they are wanting to hatch some chicks. I should charge them mor per dozen then if thats the case!!!