Why would one want to buy parrot eggs?
Do you want parrots as a pet, or to breed for fun/profit?
Either way, the best pets come from co-parented babies. Babies that are hatched naturally by their parents, and raised by both the parent parrots AND the human caretaker. This is, developmentally, going to produce the best socialized pet that knows it is a parrot (a lot of behavior problems stem from parrots thinking they are humans, or close to this concept) but learns to trust and respond to humans from day one.
If you want a pet parrot, this is the most ideal situation.
It is also the most ideal situation if you are a breeder. There are not many breeders in the USA that do this-- but, guess what? They make more money off of their birds and have waiting lists for people wanting their birds. People are getting more educated about parrot care and realize that it can be a lifelong commitment-- like a child-- and more people are going into it prepared and wanting to make the right choice.
Yes, it takes more time than just letting the parrots breed themselves silly (but it takes a lot less time than being the only 'parent' and hand-feeding a baby until it is weaned!!). Yes, it technically costs you more (time=money), however you can ask higher prices for your birds.
I regret that I simply cannot understand why someone would want to buy parrot eggs...