I agree with the other two posts i have been following another expact site and on it at the moment a skilled independent visa if using the online application is taking about 4 months this is were you front load every thing ie the medicals and police clearance forms they nearly ask for them as soon as they receive the application and money.
A sponsored visa is much quicker from 4 weeks to 8 weeks may be 10 weeks all depends how straight forward it is and if the employer has ever sponsored before.

cost wise for a skilled independent visa it is $300 for skill assessment then the visa cost is $2060 then you would have to add in what ever price the doc would charge for medicals and xrays.

here is the link to the website Professionals and other Skilled Migrants Visa Charges - Outside Australia

on there you will see 1st installment and 2nd installment the 2nd installment is for if you a brining any family members over 18 with you as far as i know some one else might know for sure about that.

hope that helps Niamh