I started selling mine last year at $3 and it felt embarrassingly high. My third customer offered $4 and I said sure. The original customers still pay 3 but new customers are four. The birds are free-ranged often and well-cared for with plenty of space but feed is nothing special.
The local farm stand gets $5/dozen and I don't think they are organic. A local health food store gets $6 or 7, I can't remember. This is in Downeast Maine where a lot of fancy people are willing to splurge on good produce, organically raised meat, etc. (let's face it, organic produce from the farm stand is mostly for wealthy people).
Organic and free-range designations aside, I find there is no comparison between a locally grown egg and a mass-produced egg-so I say, whatever the market will bear and whatever you're comfortable with. When customers give their empties to me I always pay attention to the eggs they buy outside of what they get from me; that's a sure way to know whether or not what you are charging is reasonable.
I can't see myself making any kind of profit; it would seem like most months I at least keep up with the feed costs but I doubt if the other stuff-the shavings, grit and oyster shell-are always covered. The cost of building my coop will never be recovered. Fortunately, I have birds that provide my family and I with eggs every day if we want them, they will eventually feed us in other ways and the experience of caring well for living things, especially for a young child, is something incalculable.