Raising puppies in the home and providing them with socialization is not really an extra in my eyes. That is just... a must.
I would like them used to being handled, having their ears and paws etc played with but that is something that, if I got the puppy at 8 weeks old, would probably be easy enough for me to "catch up" on if the breeder didn't do much of it. Obedience or crate training, don't care. I can do that.
I do want an effort put in so that my puppy is off to the right start in this world. I have a preference for breeders that do lots with their puppies. If I had 2 breeders I was looking at, and they were both equal except one did more in the way of socialization, I would absolutely pick that breeder over the one that does less.