I'd second all of this - very easy to care for - and cheap! My bird, Pippa, is quite an outgoing bird but you can get ones that are shy by nature to - they all have very different personalities once you give them the time to settle in. You do need to spend time training them from when you get them and you want to get one that is young when you get it if you are only getting one as they are not so used to being with other birds then because they can get lonely and upset. If you choose to get more than one, that is when they get really loud..! They chirp to each other constantly day and night. There is nothing wrong with just getting one as long as they have enough time with people for company and things to do, otherwise they can get bored and can, in extreme cases, start pulling their own feathers out through boredom... But given some toys and time out of the cage (or a cage big enough to let them fly) they can be very happy on their own. With Pippa we have had her since she was about 2 months old - you should not be able to get a budgie younger than 6 weeks, as it shouldn't be weaned younger than that. From day 1 we intoduced her to us getting closer to her and particularing to our fingers not being scary things but something she could step out of her cage onto. After a few weeks she would happily step out of the cage onto our fingers and we moved on with her training from their. Her cage has always been a safe haven for her but the door is always open and she spends most of her time on her 'climbing frame' by the window so she can look at the world go by!They're actually very easy to care for, not high maintenance at all. There cage only needs to be cleaned once or twice a week, depends on the bird. Food is very cheap you only have to buy it every month or two cause it lasts so long. They need to be feed and watered once a day and need time outside the cage. My bird is actually very shy and prefers not to be touched so I just let him be, some birds are like this, but he still requires to have outside time. A very cheap animal to have, only need a few toys a cage big enough for them to exercise they're wings and the essentials. But But they can be loud. My Toby is always singing, though I would not call it loud cause I enjoy it, but sometimes when he wants something he will scream and I mean scream(not very often) If you do decide to get one do lots of research before you get one. There proper name is Budgies.
She goes back to her cage when she wants food or water and then when we say 'bed' at night she will fly into the cage and make her way to the very top of the cage and settle her self down for the night - when we put her towel over her cage for the night. She is then quiet till the morning when she dings a bell in her cage and we then knows she wants the towel off and to get up... She's got us well trained..!!!!
She is chatty and likes to sing - especially when you are trying to watch telly - she particularly seems to like Star Trek to be noisy to..! And as Southerngirl said, boy, can she scream when she wants something! But this is not often, mostly it is just nice little chatty sounds that come from her. A great pet overall and good to practise training on too!