I'm definitely of the opinion that you figure out what the animal is worth, add the cost it would take to prep the animal for shipping, and that's your cost.
Why should the breeder lose profit, especially if they're operating on a small margin because they may not cut the corners someon else does to price their animals lower.
It was mentioned that doing this might drive away newbie buyers who just want to buy as cheap as possible. But if these people did their research they'd know what they're getting and who it's worth paying a premium to. If they haven't done any research, then you may actually lose money if they purchase something from you, kill it a day later or do something else to harm the animal, and demand money back or badmouth you on the BOI.
Either way, set your prices what YOU think is fair to you. If it means creating "shipping days" every once in a while, where you do a number of orders simultaneously so you can lower your price then go for it. If you have a higher price than your neighbor and still get regular sales, then hurray for that too.
I'm rambling now. I'm tired.
But I think I made my point