It seems that The Economist is having an Autumn sale.
As per an earlier thread on OzBargain here (kudos to findingbargains), you can sign up as being in India to get the price down to ₹4849.50 rupees, which comes to about ~$85 AUD. Just set your location as India and use the following as your billing details:
Address line : My Place
Town/City : Mumbai
Postcode : 400070
State : Maharashtra
No need for a VPN to sign up. It will also auto-renew for ₹9699 rupees, at the current exchange rate that's approximately ~$170 AUD for another 12 month subscription when it ends. For reference 50% off a subscription when you set the store to Australia comes in at $237.50 AUD.
You can get these for free through your local library.