This deal is similar to HamBoi69's from a week or so ago but following the steps below means you only need to pay R$300 (A$94.77 via gift cards) rather than $157.67.
I am unsure whether it is normal, but the R$100 gift cards I redeemed each converted to 6 months premium single, and 18 months converted to 12 months premium family. This means rather than being R$418.90, a year is only R$300 (~A$94.77)
Step 1: Cancel your existing premium subscription to Spotify and wait for the billing period to end, or create a free account if you don't have one
Step 2: Buy 3 x R$100 Spotify gift cards from here. When redeemed from this specific seller (Wtrades), they showed up as '6 months' each, which convert to 4 months family each (from following the below steps).
Step 3: Turn on a VPN and set location to Brazil.
Step 4: Go to your 'account' here and click 'Edit Profile', an option to set your country to 'Brazil' should appear (this is greyed out if you have an active premium subscription). Save your changes.
Step 5: Click Redeem and paste your gift card code that you previously purchased in Step 2. You will see that the confirmation message will mention '6 months premium' being redeemed. Repeat this step three times, then confirm you have redeemed the three codes (R$300) here. If you attempt to redeem more than 3 of these codes, you will get an error stating that you cannot redeem more than 18 months of premium in advance.
Step 6: Go to "Planos disponíveis". Under 'Assinar', press the down arrow next to 'Assassinatura mensal'. This is the monthly family subscription and it should say R$34.90/month (It's easier to understand if you ask your browser to translate to English).
Step 7: You should now see a summary of the subscription type you've selected with the date of next payment. Confirm that this is 1 year from today (or thereabouts).
Step 8: Beneath the summary, you'll see a payment gateway show up with some Brazilian payment options. Look beneath them and you will see an option called 'Mudar pais' in the footer. Click on it. Choose Australia from the list, so that your account is still Australian after the sign-up process.
Step 9: Choose PayPal as the payment method and follow the prompts to finalise. Your PayPal won't be charged until the date stated in the summary.
Step 10: After confirming, choose your normal Australian address for the premium family as you normally would, and tell your 'family' members to do the same.
Step 11: …
Step 12: profit???
I just tried this and after changing my country back to Aus it says - "Your next bill is for $18.99 on 10/3/23." so I think I've been charged Australian pricing..