Have you EVER relied entirely on welfare? I have. Do you know what it's like to live on an extremely tight fixed income? There is only so much money, period. As I said, you ask someone on a highly fixed income pay for a urine drug test, and there's a good chance they miss paying their electric bill that month. More and more utility companies are charging you if the bill is late and are turning off services sooner and sooner and charging you if they've turned off services and need to turn them back on. Expecting welfare recipients to pay for their own drug screens is cruel and demeaning. Trust me on this, the govt. has managed to make asking for help when you need it already demoralizing enough as it is.
By all means, if they fail the drug screen, penalize them, prosecute them even, but there is no reason to charge people when a significant bulk discount contract could easily be worked out between the state and the lab.