With about $15,000 you could put down 3.5% on a deal like mine but in my particular situation I know my seller won’t pay 100% of closing costs because it’s an off market deal and a good price already.

Those builders pay them a fee to be shown on their site. 

This will confirm what the lease terms and actual rents the tenants are paying. 

I do not plan on paying for the service that she signed up for but also not clearly sure how I can help.

After that, they have to pay rent, utilities, and other costs even if they aren't going to occupy for another month.

You can ask seller to pay closing costs to help reduce costs. 

When you are a new investor and want to build you will pay 2-3x more than you expected and it will take about 4-6x as long as you think going ground up.

Issue is he is paying 750$ a month for the 3br/1ba unit, market value for the area for the same type of unit is $1,819.  

Once you find a house that you believe would be a good rental, meaning desirable to your target market of customers (people within a couple of mile radius of the place), and all of the costs of monthly ownership that you can accurately project fall below the rental amounts that you project that you can get from your target customers, then you have a possible business asset that you can use to produce income, and have renters pay down the mortgage, while hopefully it goes up in value at least with the rest of the economy. 

Don't get me wrong, I feel like a good PM is invaluable and have no issues paying one their 10% to properly manage my property and take away my headaches.