I have 8 males. The first 3 were a coincidence & I wasn’t going to go above 4 so got another male. Mine are largely happy, except I believe Ernest, #8, would like a female based on observed behaviour.
Obviously 16 budgies would be too much, but I feel for him. I’m not sure it’d be the wisest move to get a lone female & expect the 6 with buddies not to fall out over his potential new friend.
Of course, this means I avoid the ethical dilemma of eggs & what to do.
I agree with Ripshod about a vet fund. I do this. If I were to insure all my pets individually, I’d have a hefty monthly bill. But you need to be disciplined & truly set the money aside.
If noise is a factor, I’d not go above 4, 2 depending on the building’s construction. More than 4 is very noticeable, but that could just be because mine are all males.
Also, don’t be like me. Get to really know your budgies early on before getting more. My tamest are my first two - not a coincidence. But the bravest is #7, so maybe it’s down to personality.
Lastly, if you want any to potentially share a cage, get them at the same time! Otherwise one budgie will claim a whole cage & never share.
If you’d like multiples, I’d honestly recommend either 2 or 4, due to your noise concerns. And I’d recommend you get them two at a time, having set up two identically sized flight cages.
Edited to add that air quality is another consideration. I just got another Rabbit Air filter. You only get one set of lungs. Having read a lot about hypersensitivity pneumonitis in people recently I decided it was necessary. You’ll need to budget for at least one good filter no matter the species of bird.