In Australia, bitcoin can be used as a currency or an investment, although it currently is not considered money (ie Australia/US Dollars). There is no prohibition on the use of bitcoin.
In regards to safety, please be aware that there are many scams that operate through bitcoin. We recommend only creating an order if you have access to your Bitcoin Wallet and are certain that you will be able to access the bitcoin once sent to you. Bitcoin transactions are irreversible, so once we send funds it's not possible to retrieve them.
Always remember - if it sounds too good to be true, it probably is!