I am an agent in the Triangle, ask your agent to run comps and if your offer is in the neighborhood of comparable properties, than I would not consider it a low ball offer. Keep in mind the condition of the property is also a consideration.
Hope this helps!
Although I'm not in your area, it is always wise to try and speak Realtor if you have an opportunity. In a perfect world, you could have your Realtor communicate with the Sellers Realtor. An agent can get a feel for the other party and it may give you a starting point. Please remember the other agents primary job is to protect the best interests of his clients and in some instances you may not get much information. If you do send in a lower offer, in my experience, I have submitted comparables in the area to substantiate the claim. You may also write the Sellers a kind note expressing your intentions, many times by showing a personal side to an offer you may be able to appeal to the Seller
What's important is to start the negotiating process.