Hi @Caban ,
The key advantages of a digital, or smart meter, are more timely access to your usage data, and less reliance on on-site meter reads for accurate billing. Other Neighbourhood users might be able to share more, but for now take a look at our Digital Meters help page for more info, including on installation costs.
The short answer is that the upgrade to a digital meter is free of upfront costs unless remedial works are required to ensure the site is safe and suitable.