This is why most wholesalers are terrible because their numbers are never even close on the repair costs.

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

If you plan to hold do a Cost segregation if you want cash now.  

The goal is to give CRE professionals more accurate pre-construction cost estimates and prevent costly surprises.I’d love to hear from the seasoned developers here:How are you currently handling site cost estimation, and what’s missing?

If the return elsewhere is better, selling may make sense.

You'll end up finding out if there is no motivation to sell at a certain price, then it is not worth consistently asking for the same price that the person said no to. 

It feels good to have all that depreciation from a cost seg. 

(So you might be upside down after selling costs if you have to sell?)

Never sell occupied unless you’re losing money hand over fist. 

Selling the PropertyIf your parents decide to sell, they could: Sell As-Is: At a current appraisal of $350k, they could walk away with a sizable profit (after transaction costs like realtor fees, taxes, etc.).