Initially I thought the one foot height was too short but after filling them, I realized higher sides would need more bags of soil/humus/manure so the higher sides would cost more and cost more to fill.
I did get humus/manure 2 cu ft bags at Walmart for $1.88 earlier this year and was able to fill this bed, but that price no longer available...
I have been composting a huge hill of fallen leaves and grass clippings from last year. I’ll try to fill the two new beds with that. I’ll put tomatoes, cukes and sweet potatoes in them this week.
I have a huge compost pile of leaves and vegetation. Also a person can line the bottom with logs/limbs of trees in the fall for filler. I saw this on a YT channel and when he moved the beds the next year all of the logs were dissolved in one years time. I wouldn’t have believed it but he showed it on camera. Also I can buy compost by the trailer load at bulk rate.