Do to an anomaly pertaining to the appraisal district, the total value of the two lots was divided equally between the lots instead of allocated by market value.  

Late fee is $77.50 and then the rent also is 1.5% after the first five days which take 18% annual and divide it by 365 to get a daily interest rate then multiply 1550 by that. 

Gross rent multiplier (GRM) A method that divides the purchase price by the gross annual rents when the property is 100% occupied.

Further you should look at how many nights you were occupied across all units here and divide $25,000 by that number.

That 2nd floor unit I would like to divided into 2 apartments.

This will vary based on region but in general 2 – 5 points, 9% - 16% APR (meaning this is the annual rate so divide it by 12 to get the monthly interest amount), and documents fees can be from $600 – $1,900.

@Jason Dubon I take the cost of all appliances and divide it by 5 (avg lifetime of appliances these days) to estimate annual cost of appliance replacements.

We simply charged 1% service fee.. so if the coupon ( in those days was 15%) We dragged 1% and divided up 14% to our fractional owners..

I chose to divide the two floors and put a locking door between the two at the stairwell.

You get a Capitalization Rate (CAP Rate), which equals your annualized return by dividing the Net Operating Income (you had gross in your narrative) by the purchase price.