It’s all about learning to mcguiver shit. If you have some land/trees keep all the leaves, branches and yard debris, + some cardboard boxes. I fill like a foot or two of every big bed or container that way before I use soil. Cheap material for containers like using big plaster 55g drums cut in half or the top cut off can be found easily. I like to use galvanized roofing sheets with some framing for large beds.