You can sell plasma, can you still sell your blood in the US? I know you could on one point, but people with blood-borne illnesses shouldn't give blood, and with a financial incentive there were problems with people lying about it.
Yes. It ends up being unprofitable to buy from donors directly, but it is still legal. There is also a thriving secondary market in selling donated blood, the Red Cross for instance makes a large amount of money selling blood.