Breeding Budgies is easy enough.
First, make sure you have a proper breeding pair. This means you did not buy them from the same shop, in the same city or even anywhere in your province. Chances are you are buying brother and sister, or at the very best a great granddaughter and her late uncle's twice removed nephew who mated with auntie who got bred from her own middle brother. See the budgie introductory moan about inbreeding and bad budgie blood in Gauteng, and please don't join the monetised march to budgie martyrdom. ...Or any other get-rich-quick breeding scheme you have bubbling in your noggin. On the other hand, almost two percent of new humans are autistic, so poisoned blood is fashion. Don't do it, dear humane human, if you think the money is worth the pain, then

drive far away and go get fresh blood, okay?
Anyway, so you have your breeding pair, now you must make sure the habitat is appropriate. From what we see, they want a nesting hollow, a regular supply of fresh food and fresher water, and off they go. We know our habitat is not yet perfect, because we are lucky to get two chicks, but apparently six and more is quite normal for budgies. Budgies tend to compete for nesting space, just as they compete for mates. This can become quite violent, and many a budgie has had to be coddled back to self confidence and life. They get bullied so bad, they sit in a heap and simper. In worts cases, they seem too afraid to move from their corner. During bad weather, make some plan to keep such an outcast safe against exposure, especially at night. They really wane where they sit and sulk, but as soon as there is new companionship, life brightens up again. Make sure there is also new nesting space available, otherwise the same thing will happen. They even throw each others' eggs out, trying to confiscate breeding space. This may be the reason we only get one baby at a time, the last egg laid before sitting commenced, all the others thrown out while the mother is out eating?
Anyway, so you have good DNA, fresh-fresh water, a nesting box and then the food runs out. Your budgies will immediately disrupt the breeding process if the food runs low. Chicks are not hatched, hatchlings are not fed, it is a mess. Make sure there is ample food available during the entire breeding cycle. In any case, there is hardly a thing such as budgie food shortage. See the feeding section and our GREENPETS HERBAL for some interesting facts about budgie food and treats.
You will know your new budgie has been fully baked when it leaves the nest, nearly fully grown and a few weeks from breeding maturity. To determine the sex and maturity of your bird, go see the article on sexing your budgie. Go on, it's free....