Fuck no! Lowering the cost of keeping people in prison would make it even easier for the government to lock people up for smaller crimes and with bigger sentences. It's even worse with the privatised prison system that the US has. They already know the "market price" (what the government is willing to spend) so adding "free money" into the equation just makes it easier for them to raise prices and end up pocketing even more money than they already do.

Framing it as offsetting the cost would also make it very easy to increase the cut, bit by bit, until it gets to a truly unreasonable level. And since the person is already in prison and we have to pay for them no matter what, why would they choose to work if the deal is so bad?