Excellent post Deborah, and an important one too! Since budgies are so plentiful and easy to acquire, this tempts many people both young and older to simply buy a male and female without any regard to knowledge - previous posts here have said it well.
I also wanted to touch upon another aspect that really NEEDS to be looked at and taken seriously when breeding. Not only knowledge on basic budgie care, but the lack of acknowledgment of contagious avian diseases and their control really gets to me!! This is sadly not something that will go away if ignored by inexperienced bird owners and breeders. Quite the opposite. There will always be contagious viral (deadly and incurable in most cases) disease in captive (and wild) population, but not taking precautions with contagious disease seriously (and bothering to learn about it in the first place) is what will keep these diseases all too common in our captive bird community.
Not only with budgies, but yes I'm talking about budgies because not only is this a budgie forum, but also because budgies are common, there are SO many inexperienced and ignorant "backyard breeders" of budgies, who don't know the first thing about disease control, that it truly scares me. Because of this I don't go to bird marts anymore, and I only like to buy birds from reputable breeders who use the closed aviary system of disease contol. Yes I bought Twigs and Mink from stores, but generally speaking that makes me nervous. I got them tested for several of the more common diseases upon buying them. The tests cost twice as much as Mink and many times more than Twigs. I don't care, it was worth it. I once had a Pionus parrot who I got at a small bird store. I thought the owner was nice, but they weren't knowledgeable I found out later. My bird died of PDD and vet said it was most likely from the nest (as PDD usually is). She was bought by the store from a broker who got her from who knows where.
Sorry to go on, but I just wanted to stress something I know is not taken seriously enough by many in the pet bird community.
Again, this is a great thread Deborah