Grumpy - with respect, although a financial spin may be placed on death in some societies, the respect and attendant ceremony offered to the dead crosses every culture^(I am happy to be corrected on this; back of my head says there were 2 exceptions which I can't now locate)^ regardless of wealth or absolute absence of materialism i.e Papua New Guinea, some of the Amazon tribes etc .
The process has much to do with the psychology of those who are left grieving and elaborate rites have taken place for thousands of years.
I also would rather go out in a cardboard box than see money wasted on an expensive funeral, but my daughters are appalled by the idea that I might not have a service and the attendant "fuss".......and I would take a guess that your own loved ones are less than enthused by the garbage bag concept.
The ceremony matters to the people we leave behind.