Six hundred square foot affordable private homes with shared community amenities. Sure; it's called a trailer park.
On individual one acre lots? That depends. If you want the homes to be in the middles of their respective lots, widely spaced apart, then you have to lay a lot of water and sewer pipes and electric wires and streets and driveways to all of them. That's called a suburb, and it drives the cost higher than apartment rents. (It's generally considered not worth it, unless the individual homes are bigger, which is why "a trailer park but the sites are scattered through the woods instead of close together" is a rarity if it exists at all, even in places where land is cheap.) Cluster the homes instead, such as at centers where eight one-acre wedges meet at a point, and maybe it's possible.
If I were designing from scratch for some combination of economy and sustainability, in a vacuum, I'd question everything. Maybe car access to individual homes isn't needed or even desirable. Maybe each home has a composting toilet but isn't connected to running water (with bathing, laundry, and taps for filling containers centralized in shared hubs, like in a family campground). But in the present day, wherever you are, there are a host of regulations that disallow such compromises for permanent residences. No running water equals uninhabitable. No automobile access, well, be prepared to have to change that if required to allow fair housing for someone with a disability.
The most difficult issue, though, isn't affording amenities. It's balancing freedom with community responsibility in a community with lots of shared stuff. And if you're renting to own, that means someone else owns it in the meantime, and that owner (aka landlord) has to be certain you're not doing anything to the property that will reduce its value or invalidate any of its insurance policies. So be prepared to live under HOA-like rules rather than libertarian autonomy.
