It's interesting that in such a death-denying culture, that funerals have become such big business and now a "green" business. In some areas, as Tango said, upselling is very common, but this can be prevented by pre-planning and pre-purchasing your own funeral/burial. Why not just get cremated and be done with it?
I have a burial plot in my hometown and really don't care what box I'm in. The plots are not big concrete chambers, but regular holes in the ground that are covered in dirt. No matter what kind of box a body is in, eventually it will decay, just as much as a body does, leaving the ground caving in which the caretakers fill in. I will be buried under a big tree at the "top" of the old main street where I grew up and my family had lived for two full generations before me.
I am not against composting for those who qualify - and those who qualify would need to be free from certain types of diseases, as Lamb suggests. There are a lot of options now, even getting compressed into a diamond. Who knows. Maybe I'll change my mind, sell my plot and become a gem!