This past month I had my elderly father and mother-in-law die. The funerals were similar, full-fig with the wake, embalming, tarting up of the corpse and open casket for at least part of it. My father's included transfer of the corpse to a church for the wake and then the next day for the funeral service, while MIL's was just at the funeral home. Dad had a very fancy coffin. Hers included a headstone, my father's did not. Both already had plots purchased. The costs were similar, about $14 for her and 18K for him. That doesn't include the after party.
My MIL had left written instructions about 5 years ago, along with my FIL to their sons that they wanted a pretty simple burial. When FIL died a few years ago, my BIL, the oldest of the lot, bullied her into having a much fancier, more expensive shindig because he converted to his wife's religion and that's how they do things, despite the fact that MIL and FIL were not of that religion. When she died, he pushed hard for the big production, and while it was important to him, it was not something the other brothers wanted. However, family dynamics being what they are, the bully got his way.
So, I can see the advantage of pre-paying, because no matter how much you tell your family what you want, they might not honor it, even if it is in writing. But I also understand that funeral homes might not end up doing what you contracted for, especially if they go out of business.
This month has cemented my resolve for a direct cremation. My friend recently did this for her father and it was about $2K. I would like a party after, with good food, booze and a pinata.