That's not fair. For people on the national waiting list for organs, matching is based on blood and tissue type, medical urgency, time on the waiting list, and geographical location. There is no way to buy a place on the national waiting list. Doctors may let a patient die so they can transplant organs to their other patients. Every effort is made to save the patient's life before donation can be considered.
Donation disfigures the body and delays the funeral.
Most donations take place within 24 hours after death, so funeral arrangements will not be delayed. Donating organs and tissues goes against religious beliefs. Signing a donor card is pointless.