I’m not going to say that this is not commonly known but it is something that quite generally, only people of means take advantage of in today’s world.
You can purchase and prepay your “final expenses”, whether you want to be embalmed and placed in an expensive casket for burial or you can be cremated in the future and placed in an Urn at today’s price and not pay the inflated prices in effect at your eventual demise!
I learned about this from my parents and was then reminded of it at a luncheon of wealthy investors that included a gentleman who owns a funeral home and crematorium.
I have made arrangements for my wife and I at 2001 prices with no idea when we may leave this earth but I know I will be saving money!