Overall Cosmetic Condition: The overall cosmetic condition of a machine has a significant impact on its worth. A Featherweight with good decals, a few scratches and paint nicks or cracks, sparkling chrome elements, and a reflecting painted surface is more attractive. The more the demand, the better the condition. Generally, machines that are at least 20 years old and still in good condition can be bought for less than $500. Functional Condition: A functional sewing machine is essential for most home sewers. Check to make sure the machine functions properly before you buy it. Use one of the many manual thread cutters available today or get a machine with a built-in cutter. Some older models only have a hole through which you can insert a coin to act as a cutter. Modern machines with drop-in bobbin cases do not need any special tool for cutting threads. Make sure you check the tension of the threading system. Too little tension will cause your thread to slip, resulting in sloppy stitching. Too much tension will cause your fabric to wear prematurely. A new generation of digital controls has been introduced into modern machines. These allow you to set the desired stitch length and adjust the thread feed if necessary to achieve it. Many older models had only mechanical controls so you were limited to those options. Look for signs of use. Older models may not have been used regularly because they were too expensive.