I think mine cost 1800 for a 400,000 LOC, but I'm a noob and may have got a bad deal.

It doesn’t matter if you sell it for more or less than your purchase price as you’ve adjusted your cost basis with the depreciation.

@Sean Graham isn’t your example paying for another cost segregation, which will cost more than a 1031, just to break even on taxes?

Hire a handyman and take the actual costs out of their deposit.

Also you need differentiate your construction costs (hard cost) vs the development costs (soft costs). 

For the low/no equity leads, they could be candidates for a Short Sale. 

Quote from @Lee Ripma: @Sean Pedeflous - I have not personally used this company but they have an algorithm based rapid cost seg which is similar to the two others I have used, KBKG and DIYcostseg.com.

After pointing this out, I would have expected the cost to be eaten by them.

Whether or not you would benefit from a cost segregation study depends on multiple factors. 

It's been a couple of years since we did an exhaustive study for BP - https://www.biggerpockets.com/blog/1031-exchange-cost. ... prices have gone up.