Transcript for Lemonade Stand
His smile is as sugary sweet as the ice cold lemonade she's selling. Squeezed it ourselves. A deal at just a dollar a glass. Sle big. The cuter you are, the more money we make. Okay. Reporter: But this young shyster has a greedy business model. It's all about the upsell. D you like a draw, a napkin, take a cookie? Reporter: Our swindler is going to squeeze his customers dry, if they let him. We're rich! Reporter: So, "what would you do?" If you came face to face with this wannabe one percenter and his side kick sister? Would you let them swindell you because they're adorable? This is no ordinary lemonade stand. We've rigged it with microphones and set up our hidden cameras outside the market basket in ritzy franklin lakes, new jersey. Lemonade! Come get your ice cold lemonade! Reporter: We're up for business and our hidden cameras are romming as this potential customer walks up. Hello. Would you like some lemonade? Sure. A cookie, or -- just a lemonade. You want a draw? Ah, sure. Yeah. Napkin? Sure. How long you guys been out here? About -- a long time. Yeah. Yeah? The man tries to strike up a conversation, but the kids are busy trying to strike up a big sale. Okay, so, that would be $15. It says it's $1. Extra large cup. Okay, I would like just a small cup then. Dollar size. Okay, add that on, so, it will be $16. Okay, I -- already used the cup, so -- the man is blind sided. I only have ten. Well, then we have a problem. Reporter: He tries for a diversion. You guys have a permit to sell stuff here? Of course we do. Sir, don't make me cry. Excuse me? Don't make me cry. Don't make you cry. I don't want to make you cry. I would just like a dollar sized cup lemonade, please. Reporter: Hey, guys, how are you? I'm john quinones. Before we sour his entire day, it's time to tell them it's "what would you do?" I was getting nervous. I was kind of blown away. I know we're in franklin lakes and things are expensive, but not $15. Reporter: We're trying to rip you off. That's why I kind of tried to negotiate them down. I actually had more than $10, but I was trying to work my way out of it. Reporter: It's not long before our next victim -- we mean, customer -- approaches. Would you like some lemonade? Sure. Reporter: She hasn't had a chance to hang up her phone before our kids start the upsell. Cookie? Yeah, one, what are they? Oatmeal raisin, chocolate chip -- oatmeal raisin. How about a straw? That's okay. Thank you. Okay. Napkin? Please. Reporter: She had no idea what she's gotten herself into. That is -- $20. Would you like a receipt. 20? Yeah. For what? For the lemonade, the straw, the cookie and the napkin. Reporter: The woman has to step back. Did she read the sign wrong? Seriously? How much is the cookie? 5. How much is the straw? 5. This is a joke, right? No. I'm an entrepreneur. I'm not paying $20 for this, guys. Sorry. I can't reuse the lemonade because I already poured it and touched the straw, touched the cookie. You touched the cookie and -- the napkin -- Reporter: The kids drive a hard bargain. Are they wearing her down? You kw what, here. Thanks. You're welcome. Reporter: Their first sale of the dame. Good luck guys. Would you like a receipt? No, thank you. I'd probably get charged for it. Have a good day. Reporter: Our money hungry saleskids are back at it. Discovering that some customers are just too sweet. Would you like -- no thanks. How about a cookie? No thanks, but I will give you a tip for being out here. Because you're doing something and you're having fun with it and you know how to do it, what the heck, why not? Here's the $10, okay? Thanks. Reporter: It turns out not everyone is such a pushover when it comes to these cute little faces. It's a dollar, right? No, five. 5? For real? We're running a business. You're running a sham here. You're running a sham. The napkin is a dollar extra, so -- what? Yeah. The napkin? Yeah. Keep the lemonade. I poured it -- so what. That's a rip-off. You're going to make my sister cry. Trying to run a busins here, sir, I -- sir? Reporter: It's been a long, hot day in the sun, but our swindlers have time for one last sale. Good. Really good. Did you guys make them? My mom made them this morning, actually. Reporter: Our tiny salesman is already reeling in these unsuspecting women. How much for the lemonade? 5. The lemonade? Sign says 1 only gets you a shot. Reporter: And they better read the fine print. Rum in it? No. Better be some alcohol. I can't take it back. Are you joking? I just showered. You set up shop to rip people off. Accusing us of false advertising? Good luck, guys. Reporter: The women are fed up but they still plunk down their $5. No tip? Here's a tip. Change your sign. I had lemonade stands when I was little for 50 cents, not $5. That's crazy. Reporter: In all, our kids made $88 throughout the day. And each time, we gave it right back. 100. Yeah, good job, guys. Reporter: Not a bad day's work, if they do say so Reporter: You can always go
This transcript has been automatically generated and may not be 100% accurate.