My donor card says parts of me will be used if they are useable and that is fine.
I have a burial plot, my wifes idea, that I do not intend to use.
My first idea, to be stood upright in a longship with a motor hooked up to my arm so I waved as I slowly drifted out to sea until the explosion engulfed the ship in flames and sent it, along with whatever was left of me, to the bottom of the Gulf of Mexico was nixed by both my children and my wife (spoilsports).
By my estimate it would have cost no more than your standard everyday funeral service, casket and burial plot.
Subsequently, I have requested that what is left of me be cremated and put into a container (I need to have one fabricated) and placed on one of my childrens mantle to eventually be passed down generation to generation until I can have my ashes scattered on Titan. This has been reluctantly agreed to; but only because I threatened to come back and haunt their toilet bowls, flushing at random and inopportune times, if they did not acquiesce.