If you really just want to have something paid off you can put extra principle down at your discretion. 

The addendum is for extra credit to the buyer for paying extra but strictly optional.

I originally had the house at 2.5%, however increased it to 3% as well as an extra 1000$ bonus.  

I greatly appreciate all of your advice and time to respond.Rob: Thank you so much for the extra input.  

I just got a phone call , guy says his house burned down .

Those extra costs add up and some investors determine that it's not worth it in the long run.  

until they burn out.

Thanks Here's a Zillow map of houses for rent near Temple University:http://www.zillow.com/temple-university-philadelph...Looks like 3 BR houses/townhomes rent for $900-$1700.  4BRs go up to and over $2000, so if you could convert an extra room to a BR, you could potentially charge up to that amount.  

I find that there are alot of extra costs you pay for no matter how efficient you get.

A house I'm looking at flipping  that is 1350 square feet  but the garage would make a great add-on for 625 square feet extra .