-How much does it cost to get them their shots? I don't know that.
-Does their disposition depend more on their breed or how you treat them (meaning, if you are affectionate with them while they are very young [no Michael Jackson jokes, please], will they be affectionate as they grow)? It's more on how you treat them.
-How much does de-clawing cost? (not sure I want to do that, but some cats with claws are just fucking destructive) You should declaw the cat only if it's destroying things. My cat was declawed without my premission and he couldn't even walk for a while because he had to wear mittens.
-Anything else I should know about. You shouldn't waste your money on expensive toys, because they only like cheap things.