The additional energy savings will be difficult to estimate compared to new vinyl windows which will be 10X more efficient that old single-pane windows.

Also keep in mind you will have recapture.My advice: take the money and invest it into a property that is more efficient as a rental.

I would first come up with an estimate for the amount of work needed with a contractor after reading the BP and J Scotts book on rehabbing so you have the background needed to understand what it is really going to take to rehab and all of the associated holding costs (taxes, interest, utilities, etc)Then I would make an offer with your realtor ensuring there is sufficient profit there.

Doing so basically ensures I will spend x amount of time per day, week, month, etc.

Previous years revenue is not that appealing, thus I have negotiated the below for the new contract. 1) New Energy efficient machine will be installed. 2) Coin Match will collect the cost of 1 cycle per machine per day and the remaining will be paid to the owner.

By utilizing the presumes 15,000 dollars a month I can gain from efficient wholesaling I will then convert that into larger apartment complexes and attempt to gain a 30% capital rate from them if possible.

What measures can I take to ensure this guy doesn't take any of my business away?

He answered every question I had, and gave me the tools I needed to follow up on leads efficiently.

The biggest thing I can think of prior to going into rentals is to have an attorney review a lease to ensure that all applicable laws and regulations are followed to protect you when you do have tenants.

Having said lien on the subject property is quite normal and the secured interest ensures the lender can get their money back or pursue legal remedies pursuant to the mortgage and note.