So $100,000 is not nearly enough to invest in a decent sized property. An apartment perhaps, but those returns are low. A decent return of a house will be above the Sydney median of $1,100,000 - and $100,000 isn't quite the 10% you need to put down the deposit.
An apartment costing say $700,000 will take decades to pay off if invested.
Believe it or not, $100,000 is PERFECT to invest in, believe it or not, shipping containers.
Yes, you read that right.
Google it if you don't believe me. Guaranteed return.