You don’t have to pay anything for final expense if you donate your body. Here at MSU a memorial service is held at our cemetery once a year for all the people who have donated their bodies in the past year, and we are building a special memorial garden in the cemetery where all the cremains will be placed. I have no idea how other universities do it, but I doubt very much that that your familiy would be charged for your cremation after you make such an ultimate sacrifice.