It really all boils down to how quickly you want results. Immediate results cost some money, but long term results really don't. Raised beds are instant gratification, whereas in-ground beds aren't (unless you spend some money). There are websites that you sign up to for tree services to drop off their wood chips/mulch for free. They don't have need or space for it, so they are more than happy to dump it anywhere. If you build your soil with that you will have incredible nutrient rich soil, but that takes time for everything to break down and get to that point. Farmers often say that the best time to build soil is 10 years ago. I have shit clay soil here, so I make due with raised beds. If I had more property I'd absolutely be getting tons of the free wood chips/mulch dropped off until I was up to my ears in it.