Bargain Buying Rules
1. Know what you want to buy before you leave, and have a good idea on Aussie prices for those particular models. They will have more models there, with some seemingly cheap - so cheap (quality wise) that they are not brought to Aus.
2. Don't haggle unless you are ready/willing to buy. I like to start haggling with the place asking the highest price. More fun. (Best reduction I have achieved is from 5,500 Baht (Thailand) down to 150.
3. Don't buy electronics unless the "sale" price (as against RRP) for the exact same model in Aus is at least 50% more.
You are more likely to get good deals at places like Georgetown (Penang) than KL, but if you are careful there are some good prices.
An interesting sideline is that, because of software piracy, games hardware is really not cheaper than Aus. Here they make a killing on games, and are willing to let the consoles go cheap to hook you into their market share. In Malaysia they need to make money on the consoles as they won't get many people paying full whack for games.
In conclusion, I can guarantee that they will be better hagglers than you are, so be careful. Be confident of what you are willing to pay before you start, and don't get drawn along.