OMG, I have went through this twice in UAE. First time the baby lived with me for 3 months, then I lost her.
The socond time I took the baby grey directly to the avian vet and in few days, PBFD was confirmed.
Sadly if one of the birds was sick, all the rest transported with him will get the desease.
Later a friend of mine who has a pet shop in Dubai, explained to me that he goes through huge measures to get healthy birds in a leagal way, which makes them way more expensive.
He explained that to be sure you import healthy birds, they have to be tested at the breeder, quarantined for min 40 days, retested, then flown in individual cages.
This of course is costly and people prefer to buy at the cheap pet shops at a much lower price. And due to this he gets rather older birds, more than 6 months old as they come from a breeder not caught wild.