If I had a quote like that I would verify the measurements and pricing.  

What safety measures do you implement to: ensure you have a serious buyer, ensure you won’t be forced to buy the home in the event that a buyer backs out or you can’t find one, and to ensure you ensure everything is being done legally?

Cody Evans measure the area you need to replace, inside area of walls, then add 25% for cuts broken pieces ETC

Take the measurements, do the math, and trust your numbers.

And 36 Other Key Financial Measures” and listening to BP, but without real numbers to practice I feel like I’m doing problem sets in school.

Most forms of payment short of cash or a wire transfer have some form of processing time, usually measured in days, even if the money "appears" in your account. 

That's not a bad thing per se; but if you are conservative on every measure, are you still making a competitive offer?  

But the measure of what something should "really cost" can not be what you think it should cost nor what you can afford.  

Just measure it.

I forgot to mention, that in Gmap, you can right click and there is also a measuring tool.