If you are thinking about a new purchase with a heloc vs a current 30 year fixed rate, this could be a good alternative.Basically, helocs are billed based on the average daily balance of the account.

Point is cash flow (positive or negative) is inconsequential compared to the appreciation assuming you do not need the cash flow to pay the bills.  

I would pay the bill and chalk it up to a lesson learned.

Quote from @Bill Hampton: @Raif JochimI recommend that have a consultation with your tax accountant and/or financial advisor on ways to reduce your taxes. 

Quote from @Bill B.: My GUESS is these homeowners have been tricked/screwed in to signing a long term power purchase agreement, often with no buy out provision.

Paying bills, invoicing, etc count, but it will be hard to say it took 750 hours! 

This led to a nearly $3,000-$4,000 bill for new installations until I clarified the situation and found that the unit already had hookups.

That's when I just decided to bill for biweekly cleaning and install hallway cameras to verify the rooms aren't accessed by anyone unauthorized.

If they are struggling then money they spend in one area affects their ability to pay other bills like rent.

If you get a plumbing bill for $100, that $100 goes directly to the plumber.