Mr. GG2 just screws together 2 4x8 beds for me about every 5 years out of the cheapest 2x10 lumber from Lowes. I fill them up with bags of cheap potting soil and 1 bag of black cow turned into each bed and I’m in business. I grow an enormous amount of veggies in those two beds and a few containers with tomatoes, Japanese egg plant, cucumber and that expensive flat leaf kale that you have to pay a fortune for at Sprouts.
Another option is galvanized steel beds, available in many length / width combos. I bought two from Amazon many moons ago and they still look as good as new. If I remember correctly, they were about $50 apiece. No doubt they’re much more expensive now, but they’re still less expensive than buying fresh lumber. And if $$$ is no object, there are those pricey Birdie’s raised beds featured on many popular Youtube channels.