After being on both end of the transaction.
As a buyer, I have had zero hatches more than one time, usually after a long trip.
As a seller I have received reports of bad hatches.
As a buyer, I report my success or lack there of to the seller, just as a FYI.
As a seller, I usually (almost always) offer a replacement set, and so far the buyer has offer to pay for half of the cost of eggs in most cases, and shipping in all cases.
Even then I have had one customer who went 0'fer on two batches of eggs. Apparently it was not meant to be.
I say ask, and be willing to accept no for an answer, as eggs sales are a gamble. Also be willing to accept somewhere in the middle ground.
When you get eggs from high quality stock, at a premium price and go 0'fer, it is oh so disappointing. Been there.