Do some hard thinking and consulting with an attorney to decide exactly how much time, effort & money you want to expend on this issue.

People in the 'spend what you have' category tend to increase their style of living (consumption) as their expendable income grows.

Rather than contend with the Charlotte zoning commission and expend a lot of money to plan a site, I encourage you to consider selling out-right as you suggested above.  

If the repairs are minor and there is little time expended, perhaps a courtesy 25% of the profit is in order (75% for you)?  

If I know I am almost fully rehabbed on projects, or looking to take a break, I will capitalize as much as possible to get some future tax deductions out of the expenses, whereas if I have a lot of projects going that are not full gut-jobs we will use more of that in the year it was expended. 

Had we been dealing with wooden planks, or plywood, on floor joists, we would have expended more effort to save the floor, but it is possible the subfloor would have to be pulled and replaced in the end.

I never stopped to think what if I lost my earning potential to garnishments or lay-off which I did and could not finish the project or I misjudged the transaction as a gain not a loss which it was, in which case I may have lost my only $10K I had as extra or expendable money throwing me out of the business into bankruptcy which it did.

Each marginal dollar is less valuable and I don't expend the same effort as I used to for money.

In all economic transactions time and money are expended.

How quickly and how much effort do you want to expend to get a deal that meets your 20% COC goal?