It sounds like YOU want to go not your parents. Do you realise how much it will cost your family to move? How much they will need to give up? In a couple of years you will no longer be living with them and perhaps you would have moved to another country and where will they be? In a country they had no desire to move to. If they want to move, they will have already looked into it.
To answer your questions - a 3 bed house in Sydney is around 600K-1.5 mill. The range is a little less in Melbourne/Brisbane/Perth (i.e. 500K). Adelaide is closer to 400-500K. However the role of a paralegal is different here - its a stepping stone role to a more senior law position, not a role in itself. So your parent will find it extremely hard to find a role here (even if they could complete the bridging courses).
Have your parents contacted the Australian Department of Immigration to find out if they are actually eligible to emigrate to Australia, because it is very difficult to do. One of your parents must have a job and experience that is required by this country - see links. If their job is not listed they are not able to emigrate.
And how old are you? If you are 18 or over you cannot cone to Australia unless you are financially dependent in your parents eg a university student.
http://www.immi.gov.au/Work/Pages/skille...
http://www.immi.gov.au/Work/Pages/skille...
I'm going to Australia this summer to survey the land, and track the annual migration of their kangaroo population.
Does your convincing argument include what visas your parents are eligible for?
Not all jobs are eligible for visas. Any job in law is not one of the eligible jobs; law is country specific.
um..... say that you miss ur friends there, or if ur really desperate, say that u can't hang with American kids
like ur getting bullied or something (only if ur desperate LOL)