Spare Kidney?

Now, my criminal justice might be a bit rusty, but I'm pretty sure that the purpose of serving time in prison is to repay your debt to society for haven broken a crime. The reason I bring this up is that there is currently a bill up for vote in South Carolina that would allow prisoners there to donate organs to people that need them in return for time off of their sentence...up to 180 days off.
I bring this up because lots of people are protesting this proposed bill as unethical. They say that the idea of the Organ Donor Program is to obtain organs without coercion or the promise of reward. Now, I understand that offering somebody 180 days off their sentence is a bit of a reward, but when you take into account that nearly 100,000 people are awaiting organ transplant surgery, and that nearly 6.800 die every year because they don't get those transplants they need to save their lives, wouldn't offering inmates a bit of incentive to donate organs be in the best service of the society they're supposed to be paying a debt to anyways.
I'm not saying that the bill is without its flaws. Diseases are rampant in prisons, and not all of these diseases can be tested for with 100% accuracy, but really, the good outweighs the bad. Given that the prison population is larger than the number of people that need organs by a huge margin (about 2 million prisoners to the 100,000 that need organs), it seems reasonable to assume that you could find enough safe donors to make up for some of the risk.
As for the health risk to the donor...well, they're in prison, and that's not exactly good for your health either. I know that if I was in prison, and I could save somebodies life by giving up a kidney or part of my liver, I would be more than willing to. Of course, that's easy for me to say since I'm not in prison, but I'd be interested to see what a survey of prisoners would tell. I'll be they'd agree with me.

George R Perry