I am thinking of a system where my investor-based agent gives me a ball park, and after that I pay contractors to go in and give me itemized bids, what do you think about that?

You really got the ball rolling after that first property! 

It’s 4bd 3.5ba nice neighborhood and planning to cover inground pool and add pickle ball court.

If you don't want to do that and you want to play hard ball with the developer then come up with a price for them to buy it from you; and make it a good high price.

If This were happening in California it would be a whole different ball game.....

Without big market appreciation (not likely) you'll need sweat equity to keep the ball rolling. 

We have them, and also additional fire protections such as a fire ball and a fire blanket. 

Any recommendations on managing the ones where i dropped the ball. 

Hello,A good rule of thumb in NC I tell my sellers about: if we get lots of showings in the first 2-4 weeks, but no offers, the price is too high by a good bit (15-25% estimated).If we get showings, and one low ball offer, the price is a little too high (5-10% too high).The longer a property sits on the market, the more likely you'll end up accepting a lower price ...better to go ahead and do a price reduction now and sell it faster, than letting it sit and eventually the market will do the price cut for you. 

Since you only have to find one property then be picky and low ball all offers, there is not nearly as much buyers out there