We've seen this plenty of times before - excited people looking to cash in on a quick buck through social media promotions and ending up participating in a large scale scam.
Navigating through the Facebook link as seen above will see you fill out an information form in what you think is an exchange for a $2,000 AU Bunnings hardware store voucher - but what you're actually doing is giving away your precious personal information, your IP address and quite possibly your computers' virus-free integrity.
There is no pot of gold at the end of the rainbow and after you've already shared the event to your friends you come out empty handed and confused.
Bunnings has officially stated that they are not involved with this competition - "Bunnings is in no way associated with any of the above activities and does not use social media for any offers or promotions. Bunnings will also never ask for personal or banking details in unsolicited communications."
Unfortunately there's no surefire way to tell if a competition on Facebook is legit or not, but generally if it looks too good to be true (or it doesn't have the word 'sponsored' written above it), it's likely that it's something dodgy.