The ETA is for short term travel to Australia
There are 2 types of ETA for visitors and business people. Both visas are valid for 12 months and will allow a person to stay in Australia for up to 3 months at any one time.
The cost of the ETA is $20 and should only be purchased from the official website Australian Electronic Travel Authority
Don’t be tempted by an agent, or other website to buy your ETA. You may end up paying more and you will be giving out your details to an organisation that will possibly bombard you with emails from agents etc…