It's a brick 2 flat with a finished garden unit in which I plan on occupying, until this discovery.

And for this lady, it sounds like she is making a power move to try and get into your desirable house, and also could be her half baked attempt at trying to stay out of debt. 

You can pay a contractor-friend (attend one of your local meetup and make contractor friends, if you don't have any) a flat fee and have him/her spend an hour or two doing some estimates with you.

Be a good host, respond fast, leave extras ( I made freshly baked cookies for every guest, they loved it.

The utility companies just charge you a flat fee for the use of the "tap".

The epoxy self-levels and the urethane topcoat (if you even go that far, makes it more indestructible) is rolled on flat.

I have so enjoyed seeing all of the landmarks and architecture out where the land is so flat! 

You could either charge a flat fee that you hope will cover the expected cost.  

No flat paint.

On the other hand its NOT robust - just a simple flat amount and "X" number of days.Im also getting an email summary in the evenings when tenants make a payment.