So it's a flip not an investment and the Airbnb numbers are estimates?

For example I’ve got to add a basement egress window and I’ve just gotten 2 estimates, one for $20K and the other for $23K.

Get 2 or more estimates to treat it, and to sister the damaged boards/beams and/or replace them.

You still have to run comps on everything, determine construction costs & estimate ARV, carry & commission costs, etc to make sure that deal in that market makes sense.

our advisor suggests selling one of our 3 rentals to pay off high interest adjustable debt which will free up cash flow due to our high interest adjustable HELOCs  he also thinks it may be ok to sell even if we pay capital gains which I mentioned before estimated transaction costs close to $150k OUCH> which would leave us with a approx net of $350k.

Never close on their ARV and grossly out of touch with reality on their repair estimates.

., 5% might actually be high in your estimation. 

Personally, I have found that no wholesaler ever presented remotely accurate numbers (rehab estimates were well below my actual costs and ARVs VERY aggressive).  

Having trouble analyzing this deal as there are so many variables and I do not have the experiencing analyzing deals to make me feel comfortable taking the risk.Purchase price of the land would be $250,000 not including closing cost or fees, and construction for a new 3/2 home with an attached 1/1 ADU is estimated to cost around $300,000 - $400,000 finished.

If you are not going to rebuild they will settle at actual cash value/market value minus the land.There are policies out there that will settle at cash-out replacement cost but they are rare and typically offered by higher end insurers for higher end owner-occupied homes.Every insurance company uses software to determine the estimated replacement cost of a home.