Forcing a retailer to advertise a set price and not below it is illegal (here).Its not price fixing.....has nothing to do with the actual end cost.....matter of fact, the ACCC almost approved it a couple of years ago.....
You can advertise whatever price you like.
Minimum resale prices
Suppliers can recommend resale prices for their goods and services, but they can’t stop resellers advertising or charging a lower price.
www.accc.gov.au