Plans can be found here.
Online Payments on the basic plan are
$29 USD monthly fee (approx AUD $41)
1.75% + 30¢ - Australian Credit Cards
2.9% + 30¢ - International Credit Cards
2.0% - fee charge by Shopify if using another payment gateway e.g. eWay
Once sales are above $46k per month it makes sense to upgrade from Shopify Basic to Shopify.
Additional advantage of upgrade other than fees is additional staff accounts, ability to offer gifts cards + professional reports.
Pricing analysis is attached.