The only amount of money you need worry about (other than the cost of the visa) is how much you will need to live here. For that check out the sticky threads at the top of the forum - they will give you what you need to start.
the costs are divided into the following:
1- Skills Assessment (around AUD $450)
2- Application fees ( AUD $2525)
3- Medicals ( it depends on country, in Egypt it's AUD $150 per person)
4- Migration agent fees (if you use one)