I've never had good luck with hatching shipped eggs. And I don't think its always the shippers fault. It's a combination of packing, the postal service, amount of travel, temps, etc etc.
I've gotten 30 eggs once that were packed awesome but didn't have but one hatch. I've also got a dozen before that had 10 broken.
All in all I hatched about 25% with a 90% hatch rate with my own eggs.
Imo if you aren't comfortable with throwing how ever much you're spending away don't buy them. That way if none hatch you were ok with nothing. If any do hatch they're a bonus. Less disappointment that way.
When it was all said and down the chicks I did hatch ended up coming to about $30 a piece when I figured what I spent.
I wouldn't buy shipped eggs again unless they were cheap and no one seems to want to let any go cheap.
For me I try to find day old chicks with live arrival guarantee.