Crow,

In your local phonebook you will find listings for civil engineering
firms. They should be able to answer this question. Try to get a guesstimate
for their work. Ask whether the house can be saved and if this is
economically feasible. You'll need to figure out why the corner sank, how to
fix that problem, and whether the framing has been greatly damaged by this.
I think you're crazy, but maybe this house can be saved

Dave M.