I, too, have seen it done. Pretty interesting project to watch.

Don't know about the cost, though.

In a semi-detached, I've lowered the floor by having it dug out by hand, then buttressed the entire foundation wall.

I've also seen a large detached home jacked up and the foundation walls built up a couple feet before the house was eased back on them and re-connected.

Unless you're getting a really good deal on the property, or it's a prime location, I'd think long and hard about undertaking such a task.

Here is a link that might be useful: Old House, New Foundation

Holy Cow. I just spent the better part of an hour on that link. It was one of the most interesting things I've seen on a forum, ever. Thanks. Wow, I can't even imagine that renovation.

I have a 3 ft crawl and I am thinking about jacking up the house 5 feet to make a walk out basement. My quote was $30,000 for the house moving, building up the block and cement pour for the floor. Just the moving part was around 10,000. It is a relatively easy thing to do from what I understand. But I live near the shore where anytime people near the beach do a certain amount of work on a house, they have to raise it too. You would look in the phone book under "house movers". They are the same people that actually move houses around.