It doesn't matter what "you" would pay for hatching eggs - it matters what your local market will pay when you're selling on craigslist. The fact that you're getting snarky emails from said local market about your prices is a sign that your prices may be higher than that market can bear. People typically don't send that sort of feedback unless you're way off - and looking at the Philly craigslist, .50-1.00 seems to be the going rate.
The fact that your birds are rare, or special only matters if people in the local market not only know that, but care.
Straight run chicks are worth a lot more than hatching eggs - they're the best case from hatching eggs, and already have almost a month of work invested.
I'm pretty sure this guy was expecting to eat the eggs, not hatch them, and that is pretty steep for eating, even if the shells are pretty. He probably has no idea what a Maran is and just saw eggs selling for 12x what he pays in the store.
I am not expecting to sell a lot of hatching eggs, not that many people want to hatch their own, there is, as you noted a lot of risk. I'm posting for the benefit of someone who is wanting BSM's and thinking about buying eggs from ebay (for ex), or chicks mailorder. They can save expense and hassle by buying locally, they just don't know where to buy them. It's more about advertising to make contact with interested people than moving large quantities of eggs.
I found his emails amusing because at first I took him seriously and responded with details about my breeders, all of which whooshed right over his head and got a very short response back - "I was making a joke".
Anyway, I kept the emails as a reminder not to assume that someone who responds to a CL post is well informed about chickens. After conversing with people here, I tend to assume a much higher level of knowledge than is warranted with CL.