You mentioned you can do this before a client makes an offer - do you visit the place or go by elevation? 

Especially on vertical surfaces, or you will have problems with runs/drips.In other words, do not lay them down like this...Elevate them on something like this...I learned the hard way!

A couple weeks go by and they ask for an elevation certificate so they can get an estimate on flood insurance.

It’s the stairs up to the top and the elevator down.

its not based on per unit...its based on size, location to the ocean, bay, US-1, 95, etc. as well as replacement value...hurricane windows, new roof, elevated access points, etc. all make for lower costs..Like my listing for a 4 unit building in miami Beach..we have full impact windows and all the front doors are up 3 steps except 1. so we have really good coverage for under $10k/year. other buildings pay $7k and don't have flood or have very low coverage. 

It was basically a 20 acre scree field at a 30 degree angle at 10,000 feet in elevation. 

Where the opening is below the adjacent ground elevation, it shall be provided with a bulkhead enclosure.R310.3.1 Bulkhead enclosures.Bulkhead enclosures shall provide direct access from the basement.

I am also aware of Elevate. 

They will survey the property and take elevation shots.  

Two elevator shafts, equipment out of order.