Around here (Upstate SC) we were told to estimate around $50/sq ft for our planned unfinished walk-out.

We are doing a partial basement in Califoria where it isn't typical. The price we were given was to put the 20x20 space in the basement it would increase our cost by $11,000, whereas putting it above grade would be $26,000.

Upstate SC here too. Basement is walkout around 1,800 sq ft, we spent about $20,000 more on the poured walls and framing. Probably $7,000 on windows and doors. And a couple hundred dollars on insulating the ceiling.

We are buying this time but we just got the appraisal back, the appraiser included building costs to replace based on 3 local contractors prices. Ours was quoted at about $50 sq ft.

NC - was more like $25 a sqft.

But, you also have to say what is the comparison. If the lot "wants" a walkout and you do a tall crawl instead, the "cost" will be much less.

I think our total basement costs were less than $50k for 2000 sqft with poured 10 ft ceilings and open web floor trusses for ductwork. Now that didn't count the siding on the back wall or the extra brick on the sides. But tall crawl would have had those costs anyway.