On a ballpark basis, you are probably looking at $10 - $11 per SF for the basement. Don't know about excavation.

Our excavation alone came in right around 3k for a walk out basement plus removal of a few trees. They didn't have to haul any dirt away though.

Our concrete foundation inc footings, 9ft wall, and short walls for our garage came in around 25K

Then you have the flatwork. That came in at almost 10K including the garage floor, front porch, and a 250sq ft patio out back.

Our house is 2400sq ft and the garage is about 800sq ft.

After that I am not sure I could break out what the floor (Basement ceiling) came to by itself as its included in the framing. So according to our prices I would guess about 50K for what you are looking at doing.

My house to be is about 2500 s.f. and the basement, slab, driveway, front and back porch and sidewalks (not including city sidewalks (the ones by the curb)
If we go 8' = $38,000 +/-
If we go 9' = $40,500 +/-
We are in Central IL

I know it has been several years since this post -- did you end up building the basement you described and if so, what was the cost? I'm looking at doing almost the exact same thing in Alabama.