Swipe a fortune

"You said you charge a 1% fee, yes?"

"Well, yes, but only when you exchange a lower currency for a higher currency."

"So why not on the other way around?"

"As I said, it's a public service."

"So you perform this as a public service? But won't the wealthy have the highest access to larger currencies? A poor person might take a year to make a single gold"

"I suppose so, yes."

Your line of questioning continues, managing to keep his interest, until eventually you reach the point you've been waiting for:
"So how much would it cost me to get all of this?" as you scoop your arms around a hoard of gold, shifting your way towards the door.

"Eh, I'd have to count that, but probably more than I make in a deca- hey, wait, get back here with my money!"

But his protest comes far too late, as you are already well on your way out of the building, hopefully out of town entirely.