The cost of raising a larger breed litter as a opposed to a smaller breed litter is obviously more. More food, more milk, more supplemental foods, etc.. Not only does a rotti mom eat far more than a doxie, but so do the pups. And having raised a couple of larger breed litters of pregnant rescue pits, I can guarantee you that raising a litter of 10 is more work than my typical litter of 4 doxies.
Yes, it is stupid for someone to agree to such a trade off, but my brother and his wife are grown adults. So while I do offer my opinions to them, I do not tell them what to do.
As far as the breeder better preparing them, well it's very obvious that all they care about is $$$. I had posted on here several months ago about the breeder wanting to breed the dog at only 13 months old. I had a big problem with that.