How much does my card payment actually cost?

Every time you pay with a card, the retailer's bank pays a fee to your bank which the retailer must cover.

MasterCard and Visa's fees are about 83 cents for every $100 spent. American Express fees are $1.75 and Diners Club $2.09. 

Eftpos costs shop-owners about 20 cents for every $100 spent, according to the Reserve Bank of Australia.

Source: The Age