I love the Dandenong Market because the bulk-buy fruit, meat, vegies and seafood lasts us (two adults, three kids, one dog and numerous visitors!) at least a month. They also have clothing stores that save us a fortune in clothes. Some of my friends do toy shopping there as well. The store runners are pretty nice and open to haggling. If you go through a lot of food and want to save a bit of money, the Dandenong Market makes that possible.
We go late on a Saturday afternoon. The fruit and vegie section is open to negotiating a better deal if you buy lots of boxes. The meat section has great deals such as 4kg of mince for $20, 2kg of chicken thighs for $16 and so on. If you buy $50 worth of food at one stall, ask for a discount. We think it's a pretty good way to save money!