For a triplex,  one third of the property taxes is allocated to the owner portion.The rental portion is treated as a separate property, depreciated and it's separate expenses allocated to it. 

My buyer is willing to pay a few thousand over but I fear that I will be in a difficult position if they were to back out as I wouldn't have any other buyers that would be willing to purchase this contract.The agreement that I use is attached.

Argh, sorry I wasn't paying attention and missed the opportunity.

Some of the adjustable products, the payment stays the same, but the principal to interest allocation changes to the point where people are only paying interest and are now in a negative amortization where the amount they owe is actually going up.

It is semi-durable, easy to clean, easy to install and in-expensive.

One of them which has been there for 10 years is saying she always pays her rent on 15th each month.

I will pay back the loan via the refi funds. 

I know in Oregon there are limits on how much you can raise the rent regardless of how low the rent price is and you have to pay the tenant to leave if you are not renewing their lease.

You can pay for it with an FHA loan or a standard loan.

However, I do believe that $15K and 50% of any net profits on and unknown number of deals is a steep price to pay, more especially when there are no leads included.