This includes design, drawings, submittal to city and permits! 

He required a $5,000 deposit and then a higher monthly payment with the "extra" applied to buying down the purchase price.If the buyer defaulted, he would keep the $5,000 deposit and he had the monthly payment that was higher than it would rent for.

We don't know your numbers, so can't say if it is worth it, but it probably isn't worth an extra $50K/unit, if it's an extra $50K spread across all 8 units...maybe.

Is there a way to figure out how much extra people charge for average properties in a good location vs  average location?

Remember to check and see if you need to obtain a rental occupancy permit in Northern Virginia. 

I recieved a judgement for 1400$ due march 31st and tenant leaves in 7 days or gets evicted with the verbal agreement she would sign a payment plan and leave the unit clean for giving her extra time as she had no where to go.

Now, I want security, independence, and some extra money would be nice.

Some examples:--Contact township regarding permitting process--Meeting with attorney to draft rental agreement--Contract with construction company that covers scope of work and timelines--Turning on utilities!

Search on Bigger Pockets for contact info, etc.My only association with it is that I plan on attending it, schedule permitting. 

The current owner built the second home in 2009 and has proof of inspection and permits from the city for everything.