We are looking at a house that has a crawl space that is 7-8 feet high with a walk out door out the back. (You can get to it from the door in the back of the house, but it is a "crawl space' b/c it has the duct work showing & is not even remotely finished. What would the cost be to turn this into a basement (add steps- we figure $400, pour concrete- $1500, put up dry wall & ceilings to hide duct work?)