Check out this youtuber video about owner-occupants in areas of Florida having to sell at a loss. https://youtu.be/wpKpwUhPRrA?

The pics, snippets and videos of influencers living a particular lifestyle are selling people emtpy dreams. 

Also if you burn a seller/broker, its a much smaller world in CRE, you will be hard pressed to get another deal.I did a longer video on the topic!

As a custom builder for decades, I dealt with this way more than once, especially with new subs that had not worked for me before.Back in the old days we used to just go with a verbal ok, but in the last 20 years or so, it is imperative to have a written CO (even an email sent from the jobsite) from the Sub and then I would add 20-25% and submit a CO of my own to the customer.

Initially the only person with a key was the responsible manager from the company but we found youtube videos showing how to break it - can't assign blame but something was not smelling good.

I actually made a whole video about this over on my YouTube channel Tech Savvy Landlord :) 

I watched some of your videos on YouTube and was impressed.

Find Brandon's videos on YouTube for the "four square" method of analyzing homes and practice.

Otherwise taking detailed videos and pictures for the contractor to get a good idea of budget should be sufficient to get a realistic budget. 

Of course, you won't listen to this common sense because you know more than everyone else here on BP and will have to learn the hard way.So, recommend you find and attend some local investor meetings or commit to watching all the videos and reading all the material here on BP that you can.Good luck:)