I think even the bunnings setup would be okay these days. A refundable 200 dollar deposit, then no rental costs:
Argon as an example:
https://www.bunnings.com.au/coregas-trade-n-go-gas-size-d-argon-gas_p5910384
"Never pay rent again. Purchase Argon gas including a cylinder deposit and when you are finished with your gas cylinder return it for a cylinder refund. Gas comes in a cylinder, and a fully refundable $200 deposit is required to be paid at time of purchase."
Argon as an example:
https://www.bunnings.com.au/coregas-trade-n-go-gas-size-d-argon-gas_p5910384
"Never pay rent again. Purchase Argon gas including a cylinder deposit and when you are finished with your gas cylinder return it for a cylinder refund. Gas comes in a cylinder, and a fully refundable $200 deposit is required to be paid at time of purchase."