I think Brent was way gracious to offer the half dozen. Now I'm in Alaska so if shipping down there is hard on eggs, think about them coming here. I ordered two batches of BCM from two different sellers. Box one arrived smashed to crap, to my suprise no broken eggs and 8 out of 12 hatched. Box two arrived in perfect shape, 2 out of 12 hatched. Now, I don't expect either seller to send replacements (I did egg topsy them, 8 were infertile) because no matter what a stud your rooster is, there can still be a clear egg.
Yes, it was expensive to only get 2 out of the 12 but thats the gamble you take when you buy eggs. As hot it was in the south this summer, that also has to be taken into account on what doesn't hatch.
Anyway, for a seller to offer to ship more egg, they're being gracious. I didn't ask either of my sellers to send me more eggs, they sent me what was offered and they fufilled the shipment. To ask for more eggs is a bit harsh, who is to say the buyer didn't screw the incubation, spike the temps, drown them with humidity. Risk has got to be on the buyer. If you are not willing to take the risk, buy hatched chicks, they guarantee them.