If you’re looking for a cost effective and enviro friendly solution… Pre arrange with UCSD Medical school to donate your body to them.
They harvest any usuable bits (skin for burn patients, corneas for eye patients even if you have cancer or another disease that makes the other organs unusable.) If nothing else, they can use the body for a cadaver for learning. When they’re done, they cover the cremation costs and dispose of the ashes.
Having had family members choose this option I know it has to be arranged ahead of time. And I know they are very nice when they show up at the hospital or home to collect the body. There is ZERO expense.