I was licenced to import goldfish before they banned it and your premises needs to reach a pretty high standard (which has got tougher since) and has to be gazetted. Also if you are new chances are MAF will not make life easy for you. After six weeks of quarantine and seven visits in six weeks, all by different pairs of inspectors I gave all the fish to MAF in a frozen lump. Each visit cost me nearly as much as the fish did in Singapore. My suggestion would be to try and get an importer with contacts already to bring some in for you with another shipment of their own fish, this would give the best discount on freight. I don't think you can rent space as the owner would want to be in control of their premise (you do something wrong they get their licence pulled) As a rough guide the importer would expect to make 100% on fish, freight, fees, overheads and deaths. You would probably have to be prepared to pay even if the whole lot died in quarantine.