I have always found Total Tyres in Moorabbin in Oakleigh to be great prices.. They are not yard apes who change them either they never scratch my friends painted rims whereas numerous others did.
95698666 - you'll probably talk to rob or shaun, it's at least worth a call for prices. They have a website but it is not a good representation of what stock they have.
If they (or anyone else) have good prices but aren't in your area see if your local tyre joint will do things for the same price, saves a trip then and you'll have somewhere local
They can get in rims too, not all, but I got some prices off rob. Some of the rims where cheaper than the other places around, but again try and see if your local place will do it for the same price.. or better it
Good Luck