[iHEAVENn]

We have a kitty, who is now a little over 3 years old. We got her from the humane society when she was about 6 months old.
She is NOT declawed, she IS litterbox trained, she does NOT bite, she IS neutered, and she IS just a big fluffy cuddle kitty.

Most cats learn very young to use the litterbox, so as long as you show them where their box is at their new home, they'll be fine.
If you get a Scratching post, the cat will go to that to stretch out their claws, and leave your furniture alone. You CAN teach your cat not to scratch you. Yeah they may have an accident now and then, but that's no reason to take away their nails.

Cat's wont smell, unless you don't clean up after them regularly.

Our dry cat food for 3 months is $60 (but that's because we buy her the expensive crap.)
Our canned cat food is $10 a month (But that is also because she's a spoiled little buttmunch. Cat's do NOT need canned food)
Our cat litter is $13 a month.

If you go to your local store, and write out the costs of food/litter present it to your parents to show you know how much money the cat will need on a monthly basis.