Because of many unethical procedures govt has laid strict guidelines in choosing donor for kidney
donation. And each state has different protocols followed. As for as I know unrelated transplant is done in few places in Kerala and Tamil nadu. But it as to be unequivocally proved that kidney donation is only by altruistic purpose.
Cost of procedure varies from hospital to hospital. Approximately it will cost you anywhere between 3lac to 10 lac. For documents, once you chose the hospital , they will guide you further.