I have an 18 year old Cockatiel that I have had since he was a baby. When he goes, we are not getting another one! Just know that they live a LONG time (barring any accidents), and that when they get older they are not always as cute and pleasant as they were when they were young birds. They really don't cost much other than the initial cage and toys. The food is inexpensive, he gets new toys for Christmas, and he has never had a vet visit. They can be messy. They tend to throw seed out of their cage when they are eating (be sure you have a good vacuum) and they molt a couple of times a year which gets feathers everywhere. The cages are kind of gross to clean too, but probably no worse than any other cage animal. They also do not really potty train which means they will poop on you and your furniture. Most of the time it is just a firm little one that is very easy to remove or clean, but every now and then it gets runny which is just nasty!
They can learn, but not anything like a parrot. Ours says a few words, mimics my husband's laugh, makes kissing sounds, and can whistle a couple of songs. He also makes up his own songs when he's happy, which is cute. My biggest warning is that they are LOUD. They yell- ALOT- especially when they get older. Also just because the bird you are looking at is not aggressive and doesn't bite now, doesn't mean it won't when it gets older. They pretty much all bite. It really isn't too bad...ours has never drawn blood, but he lets you know when he is unhappy- doesn't want to go in his cage, doesn't want your hands in his cage (they really don't like your hands in their cages even though you are putting food or treats in), etc. They hiss and yell at you and snap at you when angry.
Our bird was absolutely adorable as a young bird. He sang all the time, sat on me pretty much wherever I went around the house, snuggled up to me (yes, birds can snuggle, they get on your shoulder and rub their cute little heads under your chin or on your cheek), danced to music, entertained guests etc. He was that way for probably the first 8 to 9 years. When he started getting older, he started getting crankier little by little. He didn't want to hang out with us as much, he preferred to sit on top of his cage instead. He would hiss or bite or take off flying around the room when you tried to put him back in his cage (we would have to put his favorite stuffed animal in his cage and then leave the room. Once we were gone, he would go in and we could come out and close the cage door). He yelled more and more and for no apparent reason whatsoever, etc. He absolutely hates it when we watch basketball on tv- the squeaky shoes on the court drive him nuts and he will scream the entire game unless you cover him the whole time (he's done that pretty much his whole life though).
If you have any thoughts of getting a cat or dog (or have a cat or dog), the bird may not be the best idea. We got a dog when the bird was around 11. The bird really wanted to be friends with the puppy and wanted to land on her, and the dog really would rather have used the bird as a chew toy. So from then on, they had to take turns. The bird got to be out of his cage 2-3 hours a day while the dog was either locked in the back of the house (usually with my husband so she was happy) or penned in the kitchen instead of having his cage open most of the day. By then, he didn't come out of his cage that much anyway even though the door was open most of the day so it shouldn't have been that big a deal, but when he couldn't make friends with the dog, he decided to yell at her lots of the time instead.
In the last couple of years, the poor little guy has gotten so old that he really doesn't come out of his cage much. He can't really fly very well anymore, so it is dangerous for us to let him out. He gets really winded just flying a little bit, and his aim isn't too good either. I'm worried he will either have a heart attack or fly into something and kill himself, if we let him out. He doesn't really want to sit with me anymore anyway. If I get him out to sit with me, he pretty much just immediately tries to fly back to his cage, which is scary with his flying issues. So basically, when he wants our attention, he yells for us to come to his cage to talk to him. He yells for us a lot. We pretty much have to cover him anytime guests come over because he will scream the whole time they are there, and has been doing that for the last few years. He doesn't want to come out and visit them either, so I don't know what the problem is there.
In sum, he was a great pet for several years (if you don't mind the pooping and occasional molting and occasional yelling). After that, we still like the little guy (but like I said we aren't getting another bird when he is gone), but if loud noise annoys you, a cranky older bird may not be your thing!
