SOLVED. Juvenile book about a kid who sets up "no frills" money-making schemes. [s]

[Dani]

I'm looking for a juvenile/middle grades book that I read in ~2010. I believe it was already at least a decade old when I read it. From what I remember, the book revolved around a group of kids who were traveling, maybe as part of a camp or something? One of the kids was always sneaking off to set up money-making grifts, and I think he would always specifically call them "no-frills" - like he would sell milk, but the milk would come directly from a cow and go into a bucket. Definitely a US-based book, it was like one of those cheap paperbacks that are in elementary classroom libraries. Thank you!

[Ayshe]

No Coins, Please maybe?

[Sarah]

I also thought immediately of No Coins Please by (I believe) Gordon Korman

[Dani]

Yes, I looked and it is No Coins, Please! Thank you for your help!