I'd buy land lumber and an RV in a state and location with good soil, water, lumber, fishing, and access to markets -- if I were in a buying stance.

Build the structures yourself, patiently and methodically, getting good pricing on materials and doing the work yourself.

Building things to the standards of mortgage loan requirements is crucial. You can always get a licensed contractor to sign off on your work as long as you can build to or exceed their minimum standard.