Or a seller finance calculator showing the monthly payment based on negotiated price, interest rate, down payment, etc.

This is from the BP rental calculator and is exactly what I'm wanting to see, just with extra payments each month. 

Beyond the Monthly Management, Placement & Maintenance fees, all other fees in our contract are IF EVENT -> THEN fees.

Now, this tenant is saying that they don't remember any agreement and thought they paid month to month and could leave whenever.

I am a few months in and it has been going okay so far despite a few hiccups.

Can someone tell me what they pay monthly for business expenses for their software..

I knew that was not true because I had paid $780 a couple months before on a property in the same area and also my realtor told me that her clients had been paying that lower rate.

I've been on the BiggerPockets podcast twice:http://www.biggerpockets.com/renewsblog/2015/02/26...https://www.biggerpockets.com/renewsblog/biggerpoc...... and am launching my next MHP investment fund late this month (October of '18).  

The meters are rented and the monthly fee ($7.50) can be charged to the tenant on their statement. 

Of course like all meetups there are people there who have gone every month for probably 10 years and never done a deal.