In never knew the cost (in 2006) as it was wrapped up in the whole house cost and not itemized. I do know that it took two carpenters about a week to build. During construction the treads were 2x12 framing lumber and they swapped them out at the end for the cherry treads you see hear. materials in 2006 were around $2000 and included railings upstairs. Treads were milled locally from a tree on the property.