I would say that parents limited their feedings to a minimum. I can mostly see them cleaning the babies (picking up probably pieces of formula from their faces), rather than feeding them. I still feed them twice a day. The babies never ask me for food, of course
Should I feed them until 8 weeks of age, right? I will do the 8th week once a day probably. Does this sound like a good plan?

I don't know what to better do about the cage. We bought a bigger cage but were too busy to assemble it. The first egg was laid on Nov 12nd, so its about to hatch. Should I assemble the new cage and let the older chicks spend a night there, or should I try to move a whole thing (including the nestbox) to the new cage? I would hate to mess up with the nestbox so late in the incubation.

The chicks basically are out of the cage all day long.

What is a good age to send babies to their new homes? We are getting attached to them.... One chick, Bella, is landing on my shoulder or head when I am trying to feed her making feeding difficult but its still adorable

What are the good ways to sell the babies to good homes? Is craigslist good enough? How much do you guys normally ask? I have seen ads that only say "Hand fed Baby cockatiels - 30 dollars each" that sounds like a mill.

If I see dots when a pied tiel is spreading her wing and tail feathers, does it mean this is a girl?

It would be good to have the parents spend some time in the new cage to get used to it before you move the nest. Maybe they could take their meals in there. The older babies can start spending time in there immediately.

The time to stop feeding the older chicks is when they can get all the food they need by themselves. You know when they're weaned when they stop begging the parents (or anyone else) for food. Newly weaned babies will sometimes regress when they go to a new home and need handfeeding again, so it's best to wait for a week or two after they've weaned before you send them to a new home.

It's really up to you to decide the best way to find new homes for the chicks. Different people have different feelings about this. Some think craigslist is OK and others do not. The price varies depending on your location too, and in many places $30 is a reasonable price when you're buying direct from the breeder. I sell my babies for $30 to $60 depending on the mutation.

Spots and bars on the wing and tail of a baby don't prove anything, because both sexes have these markings. Girls tend to have more markings than boys and there is a wing spot sexing method for babies based on this, but it's not very reliable. Boys will lose the markings when they get older and girls will keep them for life. But pied boys lose the markings much more slowly than other mutations, so the markings don't mean much even on an adult pied.

Hmm, how the fact that the birds are from the breeder make them so cheap? I understand, this is probably the way it is, but I certainly won't think of myself as a breeder, because I am not.
After all the hard work, nerves and expenses, 30 dollars each? this is a rhetoric question though.
Petco sells them for 140, Petland for 120, our local bird store for 110. I was thinking to ask 80-100. Its not about money of course, but I have internal protest to even consider as cheap as 30 dollars. They are exotic birds and I thought they shouldn't be this cheap, just to make sure that people who buy them won't treat them like "its easier to buy a replacement rather than take bird to the vet".

I paid 140 for Cuddles, the mom, which included the cage and some food.

Does it happen that babies are not getting sold for a long time?

Pet shops have higher prices because they have more expenses. They have to pay rent on the building, salaries for employees, etc. Most home breeders don't have that much extra expense so they can afford to sell at a lower price. You can set any price that seems appropriate to you of course. But if your price is a lot higher than the other breeders in your area, it will be more difficult for you to sell your chicks.

this makes sense, thanks.

Is tap water finally OK for them? I use Ozarka in water bowls but there is also a large bowl they like to bath in, I usually use filtered tap water that I heat a little bit.

What can I do to help them look pretty again? All of them have traces of dried formula on the chest. Would spraying them with fine mist help to get rid of dried formula? I clean them as good as I can after feeding but can't get them completely clean. Trillie, their father, loves being sprayed. while the mother hates it (she takes bathes)

Is it natural for them to sleep in awkward places like on top of the mirror or sitting on pinata toy? We even have competition for this funny awkward locations

Also, is it always a case that fertile egg would get rotten in case of DIS? I don't want to think this direction but there has been a lot of shaking in the cage since the eggs been laid.

Do I need to take birds to the vet for check up before I attempt to sell them, or not necessary (of there is no visible problems) ?

I looked at the weight charts and my chicks seem to be a little underweight. 3 of them are 7 weeks today but none of them weighs 90g. They all are between 80 and 90g. Is it an issue or not?
I figured out handfeeding for 2 of them who eat as they should. Another one is eating when I restrain him on the table, but still he voluntarily open his beak. I have a problem with our pearl girl. She is very stubborn, wiggly and doing crazy movements. it seems that she does want to eat but doesn't know how and doesn;t cooperate at all. As soon as I am about to squeeze formula in her beak, she would do frantic movement so that formula goes all around. Then she would do pumping movement which suggests that she wants it but my squeeze is gone. I don't know what to do with her, I am tired. I understand its also lack of my experience that is on the way.
It would probably help to feed them more often but its not easy for me to find enough time.
The parents sitting together in the nestbox most part of the day, the father is hiding there from the chicks. The chicks are very boringly sitting doing nothing and waiting for him to come out. No fun.
The first egg is due but nobody hatched. I am worried. Can shaking in the cage be harmful for eggs? the chicks fight over sleeping spots. the cage is shaken and the nestbox is shaken but nobody messed up with the eggs. I hope that shock is absorbed by the bedding.
Mom eats very little. Once or twice a day.