The reason I say this is that with a 5+ unit a lender will evaluate based on NOI and a cap rate, so adding a 5th unit COULD (or could not) substantially increase the value of the building and make it worthwhile to refinance and pay off the existing loan (that is tied to the "old" quad) anyway.

How much is this individual paying to park a trailer there?

Sales comparison A common method that compares the property to similar properties nearby and their relative prices.

They pay their bills on time and make good tenants.

Quote from @John Mason: If you are wanting to get ahead I would pay the  100 usd on fiverr and get it done and  then go to next  step  in  your journey and then learn the way to do it on the side so that you do not lose time..hope I made sense I do that now.

All you're doing is paying for that NCF upfront. 

Some of the discounts are good, but just be aware that you will be paying a payment processing fee on top of the discounts. 

I’d look into the cost of a 500 sq. ft. garage and compare it to the potential boost in sale price.

However, chances of making a mistake or overlooking an opportunity to save are higher when it comes to rentals.The dilemma is whether it's worth paying a professional in this case.

Because we have been in growth mode acquiring properties with closing costs and rehab costs our business has been operating at a loss on paper each year not having to pay taxes for the business.