I have got both: a gym membership and a home gym. I find that I enjoy the gym membership a lot more, there is more atmosphere at the gym and it's more motivating. I find I get distracted very easily when working out at home, which makes my workouts waaayy longer than they need to be! The home gym is useful though when I need to workout at times when the gym isn't open, or I don't feel like going out.
Maybe have a look at http://www.gymlink.com.au
as they have a lot of free trial offers on there, so you could try out a few gyms in your local area and see if you like them (also, any good gym should let you have a free workout if you are thinking of joining... if not, I wouldn't even consider joining!)
You can also rent-to-buy a lot of gym equipment, ie, you rent it initially then if you decide to buy, they take the amount of rent you have paid off the purchase price.
Hope that helps