You know, the "funeral industry" makes funerals very expensive.
Just like weddings are expensive -- but it's not the church ceremony that costs you.
Likewise, a priest will say a funeral Mass for far less than 4-figures.
True, there are costs like tombstone and burial plot, but a casket CAN be plain wood -- the body is just going to rot anyhow.
If you pay to have liners, barriers, etc. put in, it might make you feel good that you're protecting your loved one from the worms, etc. but actually he's going to liquify into a putrid mess.
Much better to let nature take its course.
"Remember, man, that thou art dust: and unto dust thou shalt return."
Memento, homo, quia pulvis est: et in pulverem reverteris.