Depends on how much work you do yourself, what you pay for parts, how much your time is worth, and what your other alternatives are.
Used Focus parts are dirt cheap from junk cars.
If you do the labor, fixing all the problems would be more inexpensive than any other plan to get into a drivable car. Find a parts car and rape it for everything your car needs.
If you buy new parts, and/or pay somebody else to do the work, it would be cheaper to buy a different car that doesn't need work.