AN: Short and sweet. (Hopefully.) I had a bit of inspiration so I thought I'd share. I'm sorry it's not longer.
Jiraiya's baffled expression when he cut in and made him put everything back only to deftly select fresh replacements was amusing. "Oi! What d'ya think you're-"
"You want the small eggplants," Orochimaru interrupted, "with a nice weight and shiny, unblemished skin. It shouldn't remain indented, that indicates it's aged." He demonstrated by pushing lightly on one. "The calyx must be fresh and vibrant colored." Jiraiya tilted his head in a confused manner. "The calyx is the stem part." His lip curled. "The one you previously selected was of inferior quality and advanced age. Unless you wanted rotten eggplant I suggest you learn to pay attention."
"Well how was I supposed to know that?" he huffed, affronted.
"Observing. Select a target that appears of superior knowledge and watch for the types of produce they chose. That civilian over there for example," he nodded to a woman hovering over the tomatoes, "has a tendency to pick the freshest of the solanum lycopersicum. The inferior ones she moves to her left, the better quality specimens are piled to her right until she has at least fifteen upon which point she goes back through the fresh pile and decides which are the most superior."
"How long have you been stalking her?"
"You have no room to talk and I gathered that simply by observing her for about three minutes."
That earned him a doubtful look.
"You can learn a significant amount in three minutes of close observation."
"See for yourself, then. Attempt to ascertain which of any produce is the superior selection. If you can manage it within...say a half hour...I'll show you how to negotiate the decrease of price for your selection." He smirked. "If you can't...well then it wouldn't be a surprise, would it?"
It was so easy to manipulate the Toad Sage. Future Toad Sage.
"Hey, hey, hey! Who you callin' stupid?!"
"I said nothing of the sort. You implicated yourself."
"I'll implicate you one, alright," Jiraiya hissed, whirling around to stalk off into the market.
"You have to pay for your eggplant first."
It took Jiraiya thirty four minutes to finally select a good butternut squash based only on observing other people. They'd gone through ten different people before he figured out who knew what they were doing and who didn't. His triumphant expression quickly turned into a sulk when he realized he'd elapsed the time limit "By four minutes!"
"I can do this in less than three," Orochimaru pointed out blandly. "Four minutes is a valuable length of time. Four seconds can spell victory or defeat on a battlefield, even more so minutes."
Jiraiya clutched his squash and scowled.
"Pay attention this time, then," his teammate said, turning to the vendor. "How much?"
He wondered how long it would take for the brat to learn market haggling based purely on observation, or even if he would catch on.
About twenty minutes later, when Orochimaru was done his shopping and they were strolling out of the market. "Hey! I thought you said-"
The former-future-Snake Sannin smirked at him and vanished in a shunshin. "Baka."
Behind him Jiraiya let out another frustrated screech and then paused as he came to a realization, staring first at his groceries then at the spot where his teammate vanished. 'That was the most I've ever heard him talk.' His fingers tightened on the bags, some small thread of something warming his chest. He refused to call it hope.
...But Sarutobi-sensei hadn't even paid that much attention to him. Except to tell him that he needed vegetables. Orochimaru, the stuck up jerk, had actually taught him how to get the vegetables.
He just wanted to rub it in your face.
"Maybe. Or maybe..."
Maybe he was being sincere.
AN: Yes, I actually went and looked up the scientific name for a tomato. And researched how to tell if an eggplant was ripe.