I've spent a lot on shipped eggs that didn't hatch. $98 between last spring and this spring, I got ONE chick from last spring's single order of eggs, 7 chicks from one of the 3 orders I got this year. So $98 for 8 chicks. I have a few birds from shipped eggs, and they're great, but mostly shipped egg hatch rates have been dismal. My own hens' eggs hatch just fine, so I know the problem's not me, or my 'bator.
The first batch last spring, were badly packed, some were broken, and one chick hatched. they probably had bad air cells, but i didn't know how to check for that at the time.
This year, I had a batch that arrived just fine, but out of 26 very nicely packed eggs, I got 7 chicks. I think part of that was due to humidity problems near the end of the hatch.
Then I had some that were intended to be well packed, but a lot broken, and all with bad air cells, almost all free-floating bubbles. Replacements were sent for the broken ones, no floaters, well packed, but still damaged (mis-shapen) air cells. None of those hatched, from either shipment.
Next, I got a batch well packed, good air cells, but over half were infertile. # blood rings, the other 5 developed but never pipped. I had 3 of my own egg in with them, all 3 of those hatched.
Then I set 24 of my own, there was 1 clear, and 17 hatched.
I think I've about had it with shipped eggs. I might try a few next year, but I'm looking for local sources, so I can go fetch the eggs myself.