We started our first garden this year with a bed I made from old fence slats. Green peppers, habanero peppers, lemongrass, basil, cinnamon basil, and tomatoes. Some other stuff too that didn’t pan out or had to move. Problem is the tomatoes, habeneros, and green peppers took over almost immediately and we had to work to fight them back. Plus, neither my wife nor I eat tomatoes, peppers, or habeneros (I know, I know). Still, our friends and family seemed to enjoy them and my son loved playing in the dirt. Everyday he would run to greet me when I got home and drag me back to show me what he grew in the garden (what he picked off, usually prematurely ).
We spent $0 on the bed itself but over $100 on dirt from Lowes including soil and several bags of Black Kow which I highly recommend. There may be better sources for this but we initially thought we only needed a few bags. 7 bags later and three trips to Lowes, we were finally done. Next year, I’ll just buy a load of dirt from a wholesaler and mix some manure in.
EDIT: I will add that we apparently composted our pumpkins last year which got mixed in with the soil this year. We had a 15’ random pumpkin vine growing out of this thing and into our yard which my wife transplanted elsewhere later. Was pretty wild and yielded 6 small pumpkins which my son loved.