Hi!
I'm no expert either, but I can tell you what I know about my own BH Pi named Penny.
1.
Quiet - Hm, most of the day she is. Not inaudible, she does make some low chirping sounds and stuff, but compared to the budgies and lovebirds I grew up with, I'd deffo call her quiet. When she sees something interesting outside (especially dogs) she'll scream though, and she does scream pretty loud. So, if you want a parrot that's quiet for most parts of the day, it should be fine, although if you want one with a soft, non-piercing scream once it screams (because it will no matter what species you choose), then a Pi would be a big no-no. It is kind of ear-piercing.
I'm not sure this is what all Pi's are like, but Penny decides herself to go to sleep between 5-7 in the afternoon. With her, there's absolutely no danger of loud screams at night, thank lord.
2.
Family friendly - I'm sure not all Pi's are the same, but Penny is very friendly towards strangers in general. It is obvious she prefers me over my fiancée or a stranger, but she's not biting or screaming at anyone, and as soon as my fiancée comes home from work, she flies to him to get some scritches. I'm not sure if this is a result of good socializing training from when she was very little, if it's just her personality or if it's a trait common to the species in general, but she's very easy-going around most people

I can't say this goes for all Pi's though, I have read and heard about Pi's who have been very aggressive and/or completely non-interested in other people than their "mate". So, no guarantees! I recommend you have a look around the internet to find as much info about this as possible.
3.
Good for a beginner/novice bird owner - This totally depends on what you mean. Like I said I grew up with lovebirds and budgies, but I still felt like a novice when I got Penny, as I had never had a bigger parrot before (not big compared to a blue and gold macaw, but compared to a lovebird she's huge). Therefore I'd call myself a medium-sized-parrot-beginner, but I do admit I've had a lot of use of the experiences I had with my lovebirds, even when handling a bigger parrot. If you have never had a parrot before, I think maybe it's better to start off with a smaller one, if you don't know what a bite feels like you'll be surprised how hard even the smallest beak can bite... (Although I, of course, recommend you try to avoid giving your parrot a reason to bite you regardless of his/her size, it's preferable you never end up in a situation where your parrot feels like it has to bite you).
And, there's one thing you should know. Penny (and I believe, Pi's in general, at least from what I've heard) are usually very sweet and gentle. However, Penny is
stubborn as all h*ll! Once she has her mind set on something, it can be very hard to stop her. For example, she's extremely curious about biting my phone's charger cord. And this is even if I give her another piece of rope or other similar object to chew instead. It's like she won't see anything else, but the cord, once she's fixed her eyes upon it. Last week it was my headset, this week it's the cord. No idea what triggers those obsessions

So if you're not a very stubborn person yourself, beware. Of course, this may be her being different from other Pi's, but I don't know. She's not very demanding
most of the time, but once there's something she wants, she wants it
badly. Maybe it would be easier with a parrot that's more easily distracted by other fun things?
Also a very important thing about them being "easy" or not to care for; they are especially prone to aspergillosis (more so than other species, I've heard), so you have to be very careful and make sure you give a Pi all things necessary to keep their immune system in shape, and their environment clean. Although I wouldn't get any species of parrot if I couldn't provide them with this, and I don't recommend you do it either
4.
More affordable - I don't know much about the prices in the US (I'm from Sweden) so I can't really say much about it, but compared to amazon's, macaw's or grey's on the Swedish market, she was cheaper. Compared to budgies or cockatiels, she was more expensive.
Like someone already mentioned a cage can never be "too big", but I guess the distance between the bars could be. I also don't have any clue about your measuring system (I'm sorry, but the metric system makes so much more sense to me

) so I can't tell if your cage is big enough or not, but I've heard Pi's can be perch-potatoes, so it's recommended to give a Pi a big and stimulating cage to promote activity and prevent them from getting overweight. And usually, bigger cages are more expensive, so it's deffo worth taking into consideration.
I hope I've answered your questions somewhat well, and that it has helped you on your journey to parrot ownership. Please remember that whichever species you go for, there are no guarantees, they are all individuals. I've just tried to explain what my Blue-headed Pionus is like, to give you some extra meat on your bones before deciding upon which species to get. And like I mentioned above, try searching the internet for more info about the species your interested in, there are many stories out there about parrots of all shapes and sizes

Take care and good luck!
Best regards,
Sara & Penny