I produce drawing sets for permit on a regular basis. 

Consult with the historical society and be sure to pull every permit.

In other words make sure the work you do is fully permitted and performed by licensed and bonded workers.

I don't have hard numbers, but even the cheaper price of land may be completely washed out by the fact that a builder in Springfield can buy a platted subdivision for less cost per lot than in a rural town. as a new home builder myself.. the reason most of the mid west smaller areas has little to no production building is as you so accurately point out you can buy an existing home for less than replacement costs.. so until that flips.. the only new construction is usually upper end  those that have the money and want to build themselves a nice home to live in.. as a point in fact. in our market by the time you buy a lot and pay for permits etc your at 200k  before you build anything.. median price point is about 400k.. 

@Joshua Zastrow, I'm working on a new spreadsheet that analyzes more recent data -- specifically, monthly employment numbers from the Bureau of Labor Statistics and the Census Bureau's monthly report on issued building permits.

Is there a lengthy review process for permits in that area? 

PETS CRITERIAPets will be limited to domesticated dogs and domesticated cats as well as small, permanently caged animals.Certified law enforcement dogs employed only by a local, state or federal agency with proper supportingdocumentation are also permitted.2-dog limit or 2 cat-limit, for a total 3 pets limit.

He told me that replacing shedrock required me to pull a "building permit". 

I'm working on a new spreadsheet that analyzes more recent data -- specifically, monthly employment numbers from the Bureau of Labor Statistics and the Census Bureau's monthly report on issued building permits.

Most underwriters permit this without question and without further documentation if the abstractor who conducted the search produces evidence of sufficient E&O coverage.