No doubt there is plenty that are having different levels of success in this chosen field, however I'm glad that this thread hasn't been filled with stories of booming success.
To be honest you have chosen one of the most difficult businesses to enter, you have thousands of competitors you are going up against from all over the world when it comes to online sales, and that makes finding both a supplier and a market not so easy.
Plenty do make a living, plenty make just enough to top up their wages, and then there are plenty that unfortunately fail. There are hundreds of articles written about how easy it is to make money from online sales, but in reality it takes many, many, many hours of researching both suppliers and your market.
It takes a bucket load on dedication, and that's a BIG bucket as well. It's a business model that is filled with frustration, but what you always have to remember is that it is a business.
Those that are the most successful in this field are usually those that treat it as a business, and they put the work in required to make this, and any business ultimately successful.
I know you're looking for positive reinforcement, and along comes me with a big dark gloomy cloud lol, but I've seen so many get carried away when they hear of a few others success without knowing how hard the others worked, and how long it took to have that success, and then they ultimately fail because they give up to quickly.
dx has given you a different perspective on some avenues above, and it's always worth noting that ebay is not just a place to sell, but it can be a great place to buy as well, in fact as a supplier for certain stock, ebay is pretty damn hard to beat at times.
Now being in Sydney I would doubt if buying yourself a set of bolt cutters and heading of to a Kenards Self Storage complex will do you much good, and you have only very limited options to source liquidated products unless you want to import from the US, but the second hand market is a tried and true method of generating successful sales on ebay.
Places like garage sales, weekend markets, car boot sales, even thrift shops all offer a great range of products to choose for stock, and if you can talk a good bargain, then you can walk out of those place with a car load of stock, and not spend that much cash at all.
OK, so that's just one avenue, but there are plenty of opportunities to get into the market, but it all comes back to research : )
Stay positive and the best of luck with it.