This is only an 8-page story, and maybe the twist is telegraphed a bit by the peasant's understated reaction when his comrades are attacked, but I think this is a gem. Not only--as thwhtguardian said--is Usagi rarely deceived, but the old peasant doubles down on the con game by expecting payment for being a guide.
My favorite part, however, is how Usagi's anger at being powerless to stop the attack is portrayed. He stares grimly down from the cliff's edge for 3 or 4 panels, and when he later encounters a different set of bandits, his expression is wonderfully dark and threatening but not crazed. Then he demands they step aside because he's "in no mood to be gracious". Unusual bravado from Usagi. (Spoiler: they don't step aside.)
This one shows Usagi's general naivety and gullibility at times in being taken advantage of (does he even recognize this happened?) by the villagers and the peasant. Gen would have never fallen for their trickery. In the end though Usagi does end up protecting the gold even if he doesn't know it.
Gimme a home on the ol' prairie where I can sit in my rockin' chair reading my favorite old comic books of yesteryear!