Your large pine trees may be valuable to timber-harvesting companies that sell them for lumber. The largest trees supply a greater volume of wood that can be milled into boards, siding and framing materials.
You should determine exactly what you want to sell, making sure that the trees are actually on your property and are legally yours to dispose of. Prospective buyers are usually more interested in larger trees, as they produce more clear wood than smaller trees, states the Missouri Department of Conservation.
Investigate the market to learn the demand for pinewood and what the going rates are. Generally speaking, the more large pines you have to sell, the more you can charge, as it costs less to harvest a larger number of trees than just a few. Consider where your trees are located, as that can affect the price based on distance and amount of effort needed for harvesting and transportation.
The U.S. Forest Service recommends contacting your state's forestry service or a local university for help in determining the value of your pine trees. Visit the National Association of State Foresters website to find contact information for your area. The site also offers a complete listing of professional forestry consultants.