Breaking Amish on TLC by LR.
The money comes from the production company. The cast members get paid a sum of money for participating, and the production co pays for travel (plane, train, cabs), hotel, food, and any activities or purchases that happen on camera. For example, the bit about Rebecca and Abe being short on cash at the grocery store was probably staged, as there was certainly a production assistant nearby who could pay for it.
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