They usually sell for 25R each (at least from where I buy them) Capacity of a double chest is 57 stacks, or 3456 total items. 3456*25=86400, if sold for 25R each.
Chicken spawn eggs are maybe 1-2r, just for the time it takes to eggify the chickens. You can turn regular eggs into chicken spawn eggs. Just smash the regular eggs against a wall and eggify the chicks that spawn. (Using an 8x auto-cannon speeds this part up.)