BINGO!
Imagine you are a builder, and further assume this is NOT a presale. You--the new builder--will have to warranty this new home. There is great risk in that.
We appraisers have been griping about PDCs, and rightly so, because we are in essence putting OUR license and E&O on the line on the finished report for a home we did not inspect. This half-done construction scenario is similar. The only market would be an investor or a builder, either of which is taking a great risk in the quality of the prior workmanship and materials. If the drywall is up, I cannot see the framing, foundation, electrical, plumbing, etc. Yet I would have to put my name as the builder on the completed house. Small builders make their living by reputation. I would want a BIG premium to do that. It is the bank which will be eating that discount.