To be fair though Ive noticed a lot of retailers are now charging surcharges to use any credit cards (and occassionally debits too), and about a third of the time the charge is higher for Amex. I thought the RBA surcharge reforms were meant to (directly or otherwise) reduce the cost for consumers, but it's actually made it a lot worse for consumers, as card benefits/earn rates get watered down significantly and consumers actually end up paying more as more merhcants than ever are now surcharging and the surcharges have not been reduced much if at all. Pretty pathetic to be honest.
The surcharge reforms were to enable different charges based on what it actually cost, I.e. to stop those paying cash and EFTPOS subsidising credit card payers. User pays model at work, which is fair enough.
Given the growth in credit card use, prices would have likely risen anyway, just the difference is all would be paying it instead of those where the cost is coming from.