I ran some PVC through them at 1/3 and 2/3 to prevent them from blowing too much, put a slice of Trex on the outside at the PVC ends, and pinned them with a much smaller diameter section of PVC.
All in, each 4x8 bed was probably around $45 to build. I’ll probably replace them at some point with something nicer, like your metal beds. Some of the beds are bowing out some and I have a few of those weed whacker chips to deal with.
In progress pic below. The rebar is for tomato support on one side (Florida weave) and bean/pea on the other.