It is obscenely expensive to die in the UK/anywhere in Europe and it has cost families a small fortune to take care of the final trip for a loved one. Many people take out insurance policies which makes a good deal of sense.
So why not do the best thing and simply leave you body to science? Let them harvest anything that is valuable to help another person use your good vital organs, leave the rest to medical research and in the process, save yourself a packet.
Makes perfect sense to me.