Some things that will help control cost:
* Keep the footprint of structure near square. This eliminates additional lineal feet of foundation and exterior walls.
* Simple gable or single slope roof lines, no unnecessary dormers, hips or valleys.
* Keep the footprint small and simple.
* Stick with pretty "standard" windows and doors.
* Stick framed on a slab will be cheaper than a crawl space or basement.
* Build where utility connections are cheap and simple, rather than having to install a septic and well.
* Keep the electric simple; one light switch and ceiling fixture(s) per room, rather than the elaborate electric installed in most new homes.
* Eliminate vaulted and / or tall ceilings, 8' everywhere.
* Heat and cool with one simple forced air HVAC system rather than multiple units, zones, etc.
* Standard fiberglass tubs and showers -vs- tile units going into many new homes.
* Standard box cabinets and laminate counters -vs- custom stuff, granite, etc.
I doubt stained and sealed concrete will save anything over an economical floor covering. A grave driveway will be regretted, go hard surfaced at the time of construction if possible. Concrete walls will be more costly than stick framed and it would take a real long tome to see any energy savings payback.
Good luck !