I didn't feel like they pushed hard at all to upsell anything, it wasn't like a car dealer, but the options were definitely available. We chose the cheapest possible coffin because what a ridiculous waste of resources otherwise. Literally nobody was going to scrutinise it and then it was going to get burnt. I noticed the catalogue had quite a few more pages in it, though.
Interestingly my dad, newly widowed, was much more sceptical of the whole thing than me. He found the language they used quite disagreeable. They would refer to the body as "her" and say things like they are "looking after her" etc. She had lost almost half her bodyweight before death so it is kinda weird that this half matters so much. To us, of course, she had already left. We looked after her, they were just moving a body around.
But you have to think, a lot of people will pay a lot more to buy into this illusion and perhaps soften the blow of the death. I feel like you have to confront it one way or another so just get it over and done with. I just imagine the souls of the departed watching from a higher plane of existence puzzled about why we care so much about their former bodies.
You can be buried in a cardboard box. But the funeral director will be sure to remind your survivors that it's not waterproof.