When using the Gambling merchant, Im not sure if there was an amount in this button before hand but it just shows an image of coins for hitting refresh. Would be nice to know exactly how much it costs to refresh the shop.
Im wondering also if its a random amount each time for a refresh or if its a set amount.
I did not see the cost either. There should be a description or cost when you hover over the button or put the cost on the button text for each time it is clicked.