Typically what I see defined as a "serving" is one cup of raw vegetables, half a cup cooked vegetables, two cups of leafy greens (measured raw), or an apple-sized amount of fruit.
It's really not that much.
Breakfast: eggs and stir-fried onions, red pepper, and green pepper (1 cup cooked vegetables; two "servings")
Lunch: baked chicken with 1lb steamed frozen broccoli/cauliflower mix (3-4 cups as measured raw, 3-4 "servings")
snack: 1/2 cup blueberries (1 "serving")
Dinner: big salmon salad with four cups of greens, a sliced avocado, red onion, shallot, and grated carrot (2 "servings" of greens, 1 "serving" of fruit in the avocado, 1 cup other vegetables)
There you go, eight servings of vegetables, two servings of fruit, and a very nutritious day.
It can be expensive if you're not careful, but it can also be very reasonable if you are careful. I have no idea what prices are like in Australia, but here in the US, the "cheapest healthiest" vegetables are usually cabbage, onion, carrots, and romaine lettuce. That doesn't mean you can't sometimes have arugula, asparagus, and organic raspberries, but that shit adds up if you have it all the time.