Skin Game by Charles E. Fritch - Working on the theory that you can skin a sucker in space as well as on Earth, the con team of Harding and Sheckly operated furtively but profitably among natives of the outer planets. That is—until there was a question of turnabout being fair play in a world where natives took their skinning literally!
"People are basically alike," Harding said democratically. He sat idly against the strawlike matting of the hut wall and reached for a native fruit in a nearby bowl. "They're all suckers, even the smartest of them; in fact, the ones who think they're the smartest generally wind up to be the dumbest." Carefully, he bit into the fruit which resembled an orange and, mouth full, nodded approvingly. "Say, these aren't bad. Try one."
Sheckly shook his head, determined to avoid as many aspects of this culture as he could. "But these aren't people," he reminded, not happy with the thought. "They're lizards."
Harding shrugged and settled back, his grinning features ruddy in the flaring torchlight. "Humanoids have no monopoly on suckerhood. When it comes to that, we're all brothers under the skin, no matter what color or how hard the skin may be." He sighed, contemplating the harvest-to-be. "No, Sheckly, it'll be like taking candy from a baby. We'll be out of here with our pockets bulging before the Space Patrol can bat an eyelash in this direction."
Unconvinced, Sheckly stared glumly through the open doorway of the hut into the warm humid night, where a fire flared in the darkness and long shadows danced and slithered around it.
"It's not the Space Patrol I'm worried about," he said, after a while. "I don't mind fleecing humanoids—" he shivered, grimacing—"but lizards!"