I'm also 457 visa holder, arrived here over a year and just get PR approved few days ago.
Process as follows;
1. Employer sponsorship, need work for Company 6 months plus under 457 visa.
2. Prepare all docmentation. Consult with Immigration agent.
3. State sponsorship, takes about a week to ten days.
4. Lodge application and wait for notice from Immigration department for Health check.
5. Pay money for English levy if English under "functional "level.
Total fees betwwen 6 to 9k.
IELTS TEST SCORE 4.5 PLUS.
According to immigration official web site the process should be finished within 3 to 6 months if you have complete documentation at hand. www.immi.gov.au