What Snyder says is spot-on about proven dealers. You will have to make a name for yourself; good wood is always welcome. Stand behind your product, do your research, and offer your wood at competitive prices.
It is always best to select your wood in person. When that is not possible, the dealer gives a full description of the wood, and when they offer photos of the piece, both sides, top and bottom views, point out any potential flaws etc, the buyer is more likely to spring for a piece, when they know what they are getting into.
You must also develop working relationships with your customers, especially should you desire repeat business. All the dealers I know of stand behind their product. Some folks complain about prices, but please appreciate there is one heck of a lot of work that goes beyond the proper sawing and drying of the wood.