You'll get much better help & advice from the experienced members BP if you can explain what part of the process you are in, what exact questions you have, area's you need assistance in, etc. 

I gave the one side on a month-to-month lease a 60-day notice of rent increase and also explained we will be renovating it.

Whether or not there is anything to be concerned about, you are foolish if you don't spend the time and money on a GOOD REAL ESTATE attorney (practice limited to real estate, good reputation, and works with a lot of buyers) to explain the contract to you.  

@Patricia Steiner Thanks for your suggestion Patricia, I will try to explain him once today.

This video does a good job to explain: Basics to get from the seller are motivation to sell, condition of the property, timeline to sell, and their price.

Offer different unit, explain costs of moving out (new security deposit, hiring moving co, cleaning costs, new furniture) 90 days before end of their leaseSend marketing packages or gift packages to preferred employers surrounding property Reach out to old leads older than 90 days

Hi Duncan, Yes you can negotiate during the due diligence stage and you can try to negotiate at any point in the sale process until close.If you end up not being able to move forward during your due diligence, your earnest money deposit should actually be fully refunded to you, provided you put in the contract that your offer is contingent on your ability to do your due diligence.There were several deals I worked on where additional repairs were found during our due diligence that necessitated negotiation.What we did was thoroughly explain to the seller the impact of the additional expense and then offer them the options of moving forward at a lower purchase price, or working out terms at the same price (owner financing/sub2/something else), or cancelling the agreement.Usually, the seller would choose to move forward at a lower purchase price but we definitely had parties choose to cancel or finance too.If they chose to move forward at a lower purchase price, we'd write up a simple 1-sentence addendum to the original contract stating the new purchase price and have both parties sign.You may want to include a deadline in writing of when the seller must respond by before you move forward with cancellation so you don't lose your EMD.

Take this new appraisal to the city and explain the situation.

Hopefully you find a tax whiz who can explain it all to you in a way that makes sense.  

Make sure it explicitly explains the process for termination if you are unhappy with their services, but especially if they violate the terms of your agreement.3.