They live exceptionally long. (30+ years) The only thing messy is poop and seed. This can be rectified with training to not poop, and pellets, which are healthier. They can get along with another pet but have to be trained. They are usually noisy, unless trained, they love to scream and they love attention. They're very smart animals.
Nick mine was a year old and I bought it for about 200 bucks with cage and food. Monk parrots don't cost much nor lovebirds, and mine is a species that is a good talker. If you want the more expensive ones, i.e. bigger ones yeah, mine is not that big. Lovebirds are smaller. They're great first time birds. A more expensive one like African greys or Macaws require more time.
If you do get a snake depending on the breed they can be high maintenance. Young snakes can be started off in 10 gallon tanks (depending on the breed) but you will end up getting a 60 gallon or more for grown ones. Snakes usually live up to 20 years or more. Corn snakes king and milk snakes and bald pythons are good beginner snakes (king and milk snakes tend to eat cage mates so 1 to a tank) Also you have to feed it prey animals (prefrozen animals are best so clear some room) Snakes are SUPER smart they can escape pretty much anything so you have to keep a eye on it. If they do escape they head for warm areas. Before you even get one ask for a feeding demonstration so you can see if they have any feeding problems (bald pythons tend to have problems eating) Also check for scale discoloration and milky eyes these are signs the snake is sick. Let your snake outside every now and then it helps keep them healthy. Each snake has a specfic tempature their tank needs to be kept at (heating rocks tend to burn snakes so don't get one) And they need a shallow pool of water int the tank to cool off in. I'm just putting this up here because snakes takke alot of care and not mmany people know that so they end up releasing them and they die in the wild because they were captive their hole life. If you do get one I would recommend a King Snake :)