Monthly fixed flat fees seems a lot better than paying 8 to 10 % each month. 

My roommate pays $525 flat rate. 

Yes that deadens the sound a bit but none of this worked in my 100 year old American four Square home that was converted into a 2 flat back in the 60's.

Do I just flat out ask? 

This area appreciates well and it is a big 2-flat.  

The roof is a flat roof which costs about $1100 to replace in our area. 

Have you tried warm vinegar and baking soda yet?  

These are the terms I was given:3% of sale price - buyer to reimburse the difference if less$1500 minimum commission guarantee - buyer to reimburse the difference if less$189 flat portion - buyer to pay regardlessProtection Period - 90 daysDo you think these terms are appropriate?

And I know many investors like me...I'm not saying that every contractor should want to work with investors (everyone has their own business model and goals), but the blanket assumption that it isn't beneficial for any contractors to work with investors is flat-out wrong...

I think $60 is reasonable for a service call fee, as this not only includes diagnosis, but also shopping for the parts, buying them, coming back a few days later to finish the job, etc.Some places charge less for the service call, but end up taking a 50% mark up on all materials so you end up paying more.When dealing with landlords, when not an emergency and they give me regular business, I often end up just charging the time spend in their buildings at a flat hourly rate plus the parts at list price.