Some goods serve as an alternative currency, like bottles of Tide laundry detergent:
https://nymag.com/news/features/tide-detergent-drugs-2013-1/...
https://nymag.com/news/features/tide-detergent-drugs-2013-1/...
- get Medicaid to pay for supply of $30-40/can hypoallergenic formula
- sell hypoallergenic formula for $0.90 on the dollar
- pocket cash