Hi Jamie
I can't be terribly specific, never having looked for short term accommodation in Perth myself.
However, I do know that what several people have done when they have moved to Oz is to search out all the caravan sies in the area they are moving to. They are cheaper than hotels and as they are self-catering, food costs can be kept down. Most of them offer a variety of types of accommodation, at varying prices. Bear in mind though that in November Oz will be heading for Summer, and the Indian Ocean is warm all year round. The beach sites become expensive over the Christmas & New Year period especially, and the schoolchildren get their six weeks' summer hols in December through to about the end of January.
Also, look on websites like
www.realestate.com.au (which I think is the biggest of its type) and concentrate on the properties called Units. They look like bungalows to me, but apparently a bungalow is something different in Oz. It is all to do with the way the underground services like water & electricity are organised, I think. Whatever the details, Units are cheaper to rent than houses.
I've sent you a PM with a couple of other ideas. I'm sure, too, that I've seen a website called Dolphin Migration or similar - definitely Dolphin something, which is based in Perth and aims to help people when they first arrive. It might well be worth a phone call to them because they can probably tell you where the cheaper suburbs are.
Cheers
Gill